Atrioventricular valve repair using tension

ABSTRACT

A system for repairing an atrioventricular valve of a patient is provided. First and second tissue-engaging elements are configured for implantation at first and second implantation sites of the patient, respectively. First and second flexible longitudinal members are coupled at respective first end portions thereof to the first and the second tissue-engaging elements, respective. Each of the first and the second flexible longitudinal members comprises a braided polyester suture or a plurality of wires that are intertwined to form a rope structure. First and second flexible-longitudinal-member-coupling elements are coupled to respective second end portions of the first and the second flexible longitudinal members. The first and the second flexible-longitudinal-member-coupling elements are configured to be couplable together during an implantation procedure to couple together the first and the second flexible longitudinal elements.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.15/056,417, filed Feb. 29, 2016, now abandoned, which is a continuationof U.S. patent application Ser. No. 14/143,355, filed Dec. 30, 2013, nowU.S. Pat. No. 9,307,980, which is a continuation-in-part of U.S. patentapplication Ser. No. 13/553,081, filed Jul. 19, 2012, now U.S. Pat. No.9,241,702.

The following applications are incorporated herein by reference: (a)U.S. patent application Ser. No. 13/553,081, filed Jul. 19, 2012, nowU.S. Pat. No. 9,241,702, (b) U.S. patent application Ser. No.13/188,175, filed Jul. 21, 2011, now U.S. Pat. No. 8,961,596, (c) PCTapplication PCT/IL2011/00064, filed Jan. 20, 2011, which published asPCT Publication WO 2011/089601, and (d) U.S. application Ser. No.12/692,061, filed Jan. 22, 2010, now U.S. Pat. No. 8,475,525.

FIELD OF THE APPLICATION

Some applications of the present invention relate in general to valverepair. More specifically, some applications of the present inventionrelate to repair of a tricuspid valve of a patient.

BACKGROUND OF THE APPLICATION

Functional tricuspid regurgitation (FTR) is governed by severalpathophysiologic abnormalities such as tricuspid valve annulardilatation, annular shape, pulmonary hypertension, left or rightventricle dysfunction, right ventricle geometry, and leaflet tethering.Treatment options for FTR are primarily surgical. The current prevalenceof moderate-to-severe tricuspid regurgitation is estimated to be 1.6million in the United States. Of these, only 8,000 patients undergotricuspid valve surgeries annually, most of them in conjunction withleft heart valve surgeries.

SUMMARY OF APPLICATIONS

In some applications of the present invention, techniques are providedfor percutaneously repairing an atrioventricular valve of a patientusing tension. Typically, the techniques facilitate reducing ofatrioventricular valve regurgitation by altering the geometry of theatrioventricular valve and/or by altering the geometry of the wall ofthe right or left atria of the heart of the patient. In someapplications of the present invention, a first tissue-engaging elementis implanted at a first implantation site in a vicinity of theatrioventricular valve. A second tissue-engaging element is implanted ata second implantation site in a second portion of tissue that isupstream of the atrioventricular valve (e.g., in a blood vessel thatempties into an atrium). Each tissue-engaging element is coupled torespective first and second longitudinal members, which are coupledtogether using first and second longitudinal-member-coupling elements.

In some applications of the present invention, the secondtissue-engaging element is implanted after the first and the secondlongitudinal members are coupled together. For some of theseapplications, the second longitudinal member, as it is extended bypulling on the second tissue-engaging element, pulls on and appliestension to the first longitudinal member. Responsively, a distancebetween the leaflets of the atrioventricular valve is adjusted prior toimplanting the second tissue-engaging element. Alternatively oradditionally, following implantation of both the first and secondtissue-engaging elements, the distance between the leaflets of thetricuspid valve is adjusted by pulling the first and the secondlongitudinal members that connect the first and second tissue-engagingelements or by pulling at least one of the tissue-engaging elements. Forsome applications, the first and second longitudinal members are coupledat least in part to an adjusting mechanism, and the first and secondlongitudinal members are pulled or relaxed responsively to actuation ofthe adjusting mechanism. In some applications, first delivery tool isprovided which facilitates implantation of the first tissue-engagingelement. A second delivery tool is provided which facilitates couplingof the first and the second longitudinal members together, and, for someapplications, also facilitates implantation of the secondtissue-engaging element or vice versa.

In some applications of the present invention, the first and the secondlongitudinal members are coupled together using a ratchet mechanism,which allows percutaneous and remote (through a catheter) insertion,coupling, and linear tensioning of the longitudinal members. The ratchetmechanism comprises a male first longitudinal-member-coupling elementand a female second longitudinal-member-coupling element. The twolongitudinal-member-coupling elements are typically separately insertedand manipulated in the body, using two separate delivery tools. Forthese applications, after implanting the second tissue-engaging element,the operator couples the first and the secondlongitudinal-member-coupling elements together, and then tensions thefirst and the second longitudinal members by ratcheting the first andthe second longitudinal members closer together.

In some applications of the present invention, the male firstlongitudinal-member-coupling element comprises a flexible chain ofinterconnected links, which are shaped so as to define respective malecouplings. For some applications, each of the male couplings is shapedso as to define a conical feature. For some applications, the femalesecond longitudinal-member-coupling element comprises a hollow cylinderwith several internal tabs, biased to flex toward a longitudinal axis ofthe cylinder. The tabs, which may be considered to function as pawls,allow advancement of male couplings in a single direction (duringtensioning), while inhibiting (e.g., preventing) advancement of the malecouplings in the opposite direction (i.e., inhibiting relaxing).

For some applications, a flexible longitudinal guide member is removablycoupled to a proximal end of the male first longitudinal-member-couplingelement. Using the above-mentioned second delivery tool, the operatorslides the female second flexible-longitudinal-member-coupling elementalong the guide member in order to couple the female secondflexible-longitudinal-member-coupling element to the male firstflexible-longitudinal-member-coupling element. In order to allow suchsliding, the female second flexible-longitudinal-member-coupling elementis typically shaped so as to define a lumen therethrough, through whichthe guide member passes. A leading (proximal-most) one of the malecouplings may help direct the female secondflexible-longitudinal-member-coupling element onto the male firstflexible-longitudinal-member-coupling element. The guide member and thesecond delivery tool thus allow the operator to remotely andpercutaneously control the coupling and tensioning of the first and thesecond flexible-longitudinal-member-coupling elements, includingremotely and percutaneously inserting the leading (proximal-most) malecoupling into the female hollow cylinder. The guide member issubsequently decoupled from the male firstflexible-longitudinal-member-coupling element and removed from the body.

For other applications, the male firstflexible-longitudinal-member-coupling element comprises a cable, towhich the male couplings are fixed at respective, different longitudinalsites. The cable is flexible, allowing free bending but not twisting.The male couplings may include conical features.

For still other applications, the ratchet mechanism is notmechanically-based, but instead friction-based. The ratchet mechanismcomprises the female second longitudinal-member-coupling element, butdoes not comprise any male couplings. Instead, the firstlongitudinal-member-coupling element comprises a flexible cable. Thefemale second longitudinal-member-coupling element comprises a hollowcylinder with several internal tabs, biased to flex toward alongitudinal axis of the cylinder. The tabs, which may be considered tofunction as pawls, apply more friction to the cable in the direction ofloosening (relaxing) than in the direction of tightening (tensioning).For some applications, the tabs are arranged in a cascading pattern.

In some applications of the present invention, a threaded mechanism,rather than the ratchet mechanism, is used to couple the first and thesecond longitudinal members. The threaded mechanism allows percutaneousand remote (through a catheter) insertion, coupling, and both lineartensioning and relaxing of the longitudinal members. The threadedmechanism comprises a male first flexible-longitudinal-member-couplingelement and a female second flexible-longitudinal-member-couplingelement. The male first flexible-longitudinal-member-coupling elementcomprises a flexible and substantially non-twistable cable, and a wirethat is helically wound around the cable. The female secondflexible-longitudinal-member-coupling element part comprises a hollowcylinder shaped so as to define an internal thread shaped and sized soas to correspond with the helically-wound wire, so as to couple togetherthe first and second flexible-longitudinal-member-coupling elements.Rotation of the male first flexible-longitudinal-member-coupling elementwith respect to the female second flexible-longitudinal-member-couplingelement in a first direction tightens the threaded couplingtherebetween, thereby tensioning the longitudinal members. Rotation inthe opposite direction loosens the coupling, thereby relaxing thelongitudinal members.

The techniques described herein for providing an adjustable connectionbetween the first and the second longitudinal members may allowfine-tuning of the tension by the operator, both during and afterimplantation of both tissue-engaging elements, and even after formationof neointima on the tissue-engaging elements. These techniques alsoallow separate delivery of the tissue-engaging elements, using twoseparate delivery tools. Such separate delivery simplifies the procedurefor the operator as well as allowing approaches via two or moredifferent blood vessels, such as transfemoral, transjugular,transradial, and/or or transapical approaches, which may provide simpleraccess to the anchoring point.

In some applications of the present invention, a first tissue-engagingelement is implanted in a first portion of tissue that is upstream ofthe tricuspid valve. A second tissue-engaging element is then implantedin a second portion of tissue that is upstream of the tricuspid valve.For some applications, a distance between the leaflets of the tricuspidvalve is adjusted by pulling on and applying tension to the longitudinalmember responsively to pulling on the second tissue-engaging elementprior to implanting the second tissue-engaging element. Alternatively oradditionally, following implantation of both the first and secondtissue-engaging elements, the distance between the leaflets of thetricuspid valve is adjusted by pulling a longitudinal member thatconnects the first and second tissue-engaging elements or by pulling atleast one of the tissue-engaging elements. For some applications, thelongitudinal member is coupled at least in part to an adjustingmechanism, and the longitudinal member is pulled or relaxed responsivelyto actuation of the adjusting mechanism. In some applications, adelivery tool is provided which facilitates implantation of the firstand second tissue-engaging elements.

For some applications, techniques described herein are used to repairthe tricuspid valve. It is to be noted, however, that the scope of thepresent invention includes use of techniques described herein to repairthe mitral valve of the patient, mutatis mutandis.

In some applications of the present invention, techniques are providedto achieve bicuspidization of the tricuspid valve. For suchapplications, the anterior leaflet and the septal leaflet are typicallydrawn together to enhance coaptation.

For some applications, the first tissue-engaging element comprises atissue anchor (e.g., a helical tissue anchor) which is implanted in aportion of tissue surrounding an annulus of the tricuspid valve (e.g.,an anterior-posterior commissure). Typically, the second tissue-engagingelement comprises a stent which is expanded in a portion of a bloodvessel of a patient, e.g., the superior vena cava, the inferior venacava, coronary sinus, or a hepatic vein, e.g., the left hepatic vein,the right hepatic vein, or the middle hepatic vein. During the adjustingof the distance between the first and second tissue-engaging elements,the operator monitors a parameter indicative of regurgitation of thetricuspid valve. Responsively to the pulling of the longitudinalelement(s), the geometry of the right atrium is altered, thereby drawingtogether the leaflets of the tricuspid valve.

For some applications of the present invention, the firsttissue-engaging element comprises a second stent which is expanded in aportion of a second blood vessel of the patient, e.g., the superior venacava, the inferior vena cava, the coronary sinus, or a hepatic vein,e.g., the left hepatic vein, the right hepatic vein, and the middlehepatic vein.

For some applications, a plurality of second tissue-engaging elementsare provided (such as two or three), which are implanted in respectiveportions of cardiac tissue in a vicinity of the heart valve. For someapplications, a longitudinal member is (a) directly coupled to the firsttissue-engaging element, (b) directly coupled to one of the secondtissue-engaging elements, and (c) indirectly coupled to two others ofthe second tissue-engaging elements by a longitudinal sub-member.

For still other applications of the present invention, both the firstand second tissue-engaging elements comprise respective first and secondtissue anchors. Each tissue anchor punctures a respective portion ofcardiac tissue of the patient and is implanted at least in part in therespective portion of cardiac tissue. The tensioning element couples thefirst and second tissue anchors and is adjusted following implantationof the first and second tissue anchors by pulling or relaxing thetensioning element.

For some applications of the present invention, a torque-delivering toolis provided for rotating a tissue anchor, so as to drive the anchor intotissue. The torque-delivering tool comprises a torque-delivering cable,a distal end of which comprises a first coupling that is configured toremovably engage a second coupling coupled to the anchor in a controlledmanner, such that rotation of the torque-delivering cable rotates theanchor. For some applications, the apparatus further comprises ananti-entanglement device which prevents entanglement of the flexiblelongitudinal member during rotation of the anchor.

For some applications, the stents described hereinabove comprise aplurality of interconnected superelastic metallic struts. For someapplications, the stents described herein comprise a force-distributingelement providing means to connect the stent to the flexible member anddistribute tension applied from the flexible member to the stent along alongitudinal length of the stent.

There is therefore provided, in accordance with an application of thepresent invention, apparatus including:

first and second tissue-engaging elements;

first and second flexible longitudinal members, coupled at respectivefirst end portions thereof to the first and the second tissue-engagingelements, respectively;

a first flexible-longitudinal-member-coupling element coupled to asecond end portion of the first flexible longitudinal member, whereinthe first and the second end portions of the first flexible longitudinalmember are disposed at opposite longitudinal ends of the first flexiblelongitudinal member;

a second flexible-longitudinal-member-coupling element coupled to asecond end portion of the second flexible longitudinal member, whereinthe first and the second end portions of the second flexiblelongitudinal member are disposed at opposite longitudinal ends of thesecond flexible longitudinal member; and

a flexible longitudinal guide member reversibly coupled to the firstflexible-longitudinal-member-coupling element,

wherein the first and second flexible-longitudinal-member-couplingelements are configured to be couplable together to couple together thefirst and the second flexible longitudinal elements.

For some applications, the first tissue-engaging element includes ahelical tissue anchor. For some applications, the apparatus furtherincludes a torque-delivering tool configured to screw the helical tissueanchor into tissue of a patient.

For some applications, the second tissue-engaging element includes aradially-expandable stent configured to be implanted in a blood vesselselected from the group consisting of: an inferior vena cava, a superiorvena cava, and a coronary sinus.

For some applications, the first tissue-engaging element includes ahelical tissue anchor, and the second tissue-engaging element includes aradially-expandable stent configured to be implanted in a blood vesselselected from the group consisting of: an inferior vena cava, a superiorvena cava, and a coronary sinus.

For some applications, the second flexible-longitudinal-member-couplingelement is shaped so as to define a lumen therethrough, and isconfigured to slide along the flexible longitudinal guide member whenthe flexible longitudinal guide member passes through the lumen.

For some applications, the second flexible-longitudinal-member-couplingelement is shaped so as to define a coupling interface that is notcoaxial with the second flexible-longitudinal-member-coupling element,and the second flexible longitudinal member is fixed to the couplinginterface.

For some applications, a proximal end of the firstflexible-longitudinal-member-coupling element is shaped so as to definea threaded coupling, and the flexible longitudinal guide member isshaped so as to define a screw that is reversibly coupled to thethreaded coupling.

For some applications, the flexible longitudinal guide member isreversibly coupled to the first flexible-longitudinal-member-couplingelement by being looped through a portion of the firstflexible-longitudinal-member-coupling element.

For some applications, the apparatus further includes a snare couplableto the flexible longitudinal guide member so as to facilitate extractionof a portion of the flexible longitudinal guide member to outside a bodyof a patient.

For any of the applications described above, the apparatus may furtherinclude:

a first delivery tool, which (a) includes a first catheter tube, and (b)is configured to deliver the first tissue-engaging element, the firstflexible longitudinal member, the firstflexible-longitudinal-member-coupling element, and the flexiblelongitudinal guide member; and

a second delivery tool, which (a) includes a second catheter tube, and(b) is configured to deliver the second flexible longitudinal member andthe second flexible-longitudinal-member-coupling element, and to couplethe second flexible-longitudinal-member-coupling element to the firstflexible-longitudinal-member-coupling element.

For some applications, the second delivery tool is configured to deliverthe second flexible longitudinal member and the secondflexible-longitudinal-member-coupling element after deployment of thesecond tissue-engaging element.

For some applications, the second tissue-engaging element includes aradially-expandable stent configured to be implanted in a blood vesselselected from the group consisting of: an inferior vena cava, and asuperior vena cava; and the second delivery tool is configured and sizedto pass through the stent when the stent is in a radially-expandedstate.

For some applications, the second delivery tool further includes anadvancement tube, which is advanceable through a lumen of the secondcatheter tube, and is configured to couple the secondflexible-longitudinal-member-coupling element to the firstflexible-longitudinal-member-coupling element.

For any of the applications described above:

the first flexible-longitudinal-member-coupling element may include aplurality of male couplings, disposed along the firstflexible-longitudinal-member-coupling element at respective, differentlongitudinal sites, and

the second flexible-longitudinal-member-coupling element may include afemale coupling configured to receive the male couplings, allowadvancement of the male couplings through the female coupling in a firstdirection, and restrict advancement of the male couplings through thefemale coupling in a second direction opposite the first direction.

For some applications, the male couplings have respective conicalfeatures.

For some applications:

the female coupling (a) includes a hollow cylinder configured to receivethe male couplings, and (b) is shaped so as to define one or more tabsbiased to flex toward a central longitudinal axis of the cylinder,

the male couplings are shaped so as to define respective protrusions,and

the protrusions and the one or more tabs are shaped and sized to allowthe advancement of the first flexible-longitudinal-member-couplingelement through the hollow cylinder in the first direction, and torestrict the advancement of the firstflexible-longitudinal-member-coupling element in the second direction.

For some applications, each of the male couplings is shaped so as todefine one or more internal ridges, which are configured to engage theone or more tabs when the tabs enter one of the male couplings.

For some applications, the first flexible-longitudinal-member-couplingelement includes a flexible chain of interconnected links, which areshaped so as to define the male couplings, respectively. For someapplications, the male couplings have respective conical features. Forsome applications, the links are shaped so as to define respectivespherical heads and spherical receptacles, which are shaped and sized soas to couplingly receive the spherical head of an adjacent one of thelinks.

For some applications, the first flexible-longitudinal-member-couplingelement includes a flexible cable to which the male couplings are fixedat the respective, different longitudinal sites. For some applications,the male couplings have respective conical features. For someapplications, the flexible cable is substantially not twistable.

For some applications, the protrusions are shaped so as to definerespective edges, and the one or more tabs are configured to flex towardthe longitudinal axis after the advancement of the edges of the malecouplings beyond the one or more edges, so as to restrict advancement ofthe male couplings with respect to the one or more tabs in the seconddirection.

For any of the applications described above,

the first flexible-longitudinal-member-coupling element may include:

-   -   a cable, which is configured to be flexible and substantially        not twistable; and    -   a wire, which is helically wound around and fixed to the cable,        and

the second flexible-longitudinal-member-coupling element may include afemale coupling, which (a) includes a hollow cylinder configured toreceive the flexible-longitudinal-member-coupling element, and (b) isshaped so as to define an internal thread shaped and sized so as tocorrespond with the helically-wound wire.

For some applications, the wire is helically wound around the cable atan average pitch equal to between one and four times a diameter of thecable. Alternatively or additionally, for some applications, the wire iswelded to the cable.

For any of the applications described above,

the first flexible-longitudinal-member-coupling element may include aflexible cable,

the second flexible-longitudinal-member-coupling element may include afemale coupling, which (a) includes a hollow cylinder configured toreceive the cable, and (b) is shaped so as to define one or more tabsbiased to flex toward a central longitudinal axis of the cylinder, and

the cable and the one or more tabs may be shaped and sized to allowadvancement of the first flexible-longitudinal-member-coupling elementthrough the hollow cylinder in a first direction, and to restrict, byfriction, advancement of the first flexible-longitudinal-member-couplingelement in a second direction opposite the first direction.

For some applications, the male coupling is shaped so as to define oneor more internal ridges, which are configured to engage the one or moretabs when the tabs enter the male coupling.

For any of the applications described above, the firstflexible-longitudinal-member-coupling element includes a male coupling,and the second flexible-longitudinal-member-coupling element includes afemale coupling configured to receive the male coupling.

For some applications:

the female coupling (a) includes a hollow cylinder configured to receivethe male coupling, (b) is shaped so as to define one or more tabs biasedto flex toward a central longitudinal axis of the cylinder,

the male coupling is shaped so as to provide one or more protrusions,and

the male coupling and the one or more tabs are sized and shaped to (a)allow advancement of the male coupling with respect to the one or moretabs in a first direction, by pushing the one or more tabs away from thelongitudinal axis, and (b) restrict advancement of the male couplingwith respect to the one or more tabs in a second direction opposite thefirst direction.

For some applications, the one or more protrusions are shaped so as todefine a shelf, and the one or more tabs are configured to flex towardthe longitudinal axis after the advancement of the shelf of the malecoupling beyond the one or more tabs, so as to restrict advancement ofthe male coupling with respect to the one or more tabs in the seconddirection.

For some applications:

the female coupling includes a structural element including one or morewalls shaped so as to define an opening,

the male coupling includes one or more radially-displaceable arms, and

the one or more radially-displaceable arms are:

-   -   compressible by the walls during advancement of the one or more        radially-displaceable arms through the opening, and    -   following advancement of the one or more radially-displaceable        arms through opening, expandable to a first dimension that is        larger than a second dimension of the opening so as to lock the        male coupling to the female coupling.

For some applications:

the female coupling includes a structural element including one or morewalls shaped so as to define an opening,

the male coupling includes one or more radially-displaceable arms, and

the one or more radially-displaceable arms are:

-   -   compressible by the walls during advancement of the one or more        radially-displaceable arms through the opening, and    -   following advancement of the one or more radially-displaceable        arms through opening, expandable to a position in which at least        a portion of an outer surface of the one or more arms is beyond        and above the one or more walls.

For some applications:

the female coupling includes a structural element including one or morewalls shaped so as to define one or more shelves,

the male coupling includes one or more radially-displaceable legs, and

the one or more radially-displaceable legs are:

-   -   compressible by the walls during advancement of the one or more        radially-displaceable legs along the one or more shelves, and    -   following the advancement of the one or more        radially-displaceable legs beyond the one or more shelves in a        first advancement direction, expandable to lock the male        coupling to the female coupling, and

following expanding of the one or more radially-displaceable legs, theone or more shelves of the female coupling restrict advancement of theone or more radially-displaceable legs in a second advancement directionopposite the first advancement direction.

For some applications, the one or more walls of the female couplingelement are shaped so as to define at least one groove, and the malecoupling element is shaped so as to define at least one protrusionshaped so as to fit within the at least one groove.

For some applications, the female coupling includes a structural elementshaped so as to define a curved groove, and the male coupling includes aprojection advanceable within the curved groove so as to lock the malecoupling to the female coupling.

There is further provided, in accordance with an application of thepresent invention, apparatus including:

first and second tissue-engaging elements;

first and second flexible longitudinal members, coupled at respectivefirst end portions thereof to the first and the second tissue-engagingelements, respectively;

a first flexible-longitudinal-member-coupling element, which (a) iscoupled to a second end portion of the first flexible longitudinalmember, and (b) includes (i) a cable, which is configured to be flexibleand substantially not twistable; and (ii) a wire, which is helicallywound around and fixed to the cable, wherein the first and the secondend portions of the first flexible longitudinal member are disposed atopposite longitudinal ends of the first flexible longitudinal member;

a second flexible-longitudinal-member-coupling element, which (a) iscoupled to a second end portion of the second flexible longitudinalmember, and (b) includes a female coupling, which (i) includes a hollowcylinder configured to receive the firstflexible-longitudinal-member-coupling element, and (ii) is shaped so asto define an internal thread shaped and sized so as to correspond withthe helically-wound wire, so as to couple together the first and thesecond flexible-longitudinal-member-coupling elements, wherein the firstand the second end portions of the second flexible longitudinal memberare disposed at opposite longitudinal ends of the second flexiblelongitudinal member; and

a flexible longitudinal guide member reversibly coupled to the firstflexible-longitudinal-member-coupling element.

For some applications, the wire is helically wound around the cable atan average pitch equal to between one and four times a diameter of thecable. Alternatively or additionally, for some applications, the wire iswelded to the cable.

For some applications, the hollow cylinder of the female coupling isshaped so as to define a lumen therethrough, and is configured to slidealong the flexible longitudinal guide member when the flexiblelongitudinal guide member passes through the lumen.

For some applications, the second flexible-longitudinal-member-couplingelement is shaped so as to define a coupling interface that is notcoaxial with the second flexible-longitudinal-member-coupling element,and the second flexible longitudinal member is fixed to the couplinginterface.

For any of the applications described above, the apparatus may furtherinclude:

a first delivery tool, which includes a first catheter tube, and whichis configured to deliver the first tissue-engaging element, the firstflexible longitudinal member, the firstflexible-longitudinal-member-coupling element, and the flexiblelongitudinal guide member; and

a second delivery tool, which includes a second catheter tube, and whichis configured to deliver the second flexible longitudinal member and thesecond flexible-longitudinal-member-coupling element, and to couple thesecond flexible-longitudinal-member-coupling element to the firstflexible-longitudinal-member-coupling element.

For some applications, the second delivery tool is configured to deliverthe second flexible longitudinal member and the secondflexible-longitudinal-member-coupling element after deployment of thesecond tissue-engaging element.

For some applications, the second tissue-engaging element includes aradially-expandable stent configured to be implanted in a blood vesselselected from the group consisting of: an inferior vena cava, and asuperior vena cava; and the second delivery tool is configured and sizedto pass through the stent when the stent is in a radially-expandedstate.

For some applications, the second delivery tool further includes arotation-stabilization tube, which is advanceable over the flexiblelongitudinal guide member and through a lumen of the second cathetertube, and is configured to reversibly engage and rotationally lock withthe second flexible-longitudinal-member-coupling element.

There is still further provided, in accordance with an application ofthe present invention, a method including:

implanting, in tissue of an atrium of a patient, a first tissue-engagingelement, to which a first end portion of a first flexible longitudinalmember is coupled, while a flexible longitudinal guide member isreversibly coupled to a first flexible-longitudinal-member-couplingelement that is coupled to a second end portion of the first flexiblelongitudinal element, wherein the first and the second end portions ofthe first flexible longitudinal member are disposed at oppositelongitudinal ends of the first flexible longitudinal member;

advancing, over the flexible longitudinal guide member, toward theatrium, a second flexible-longitudinal-member-coupling element coupledto a second end portion of a second flexible longitudinal member,wherein a second tissue-engaging element is coupled to a first endportion of the second flexible longitudinal member, and the first andthe second end portions of the second flexible longitudinal member aredisposed at opposite longitudinal ends of the second flexiblelongitudinal member;

coupling together the first and the secondflexible-longitudinal-member-coupling elements; and

implanting the second tissue-engaging element upstream of the atrium.

For some applications, coupling together the first and the secondflexible-longitudinal-member-coupling elements includes performing oneor both of the group of actions consisting of: pulling the flexiblelongitudinal guide member, and pushing the secondflexible-longitudinal-member-coupling element.

For some applications, implanting the first tissue-engaging elementincludes implanting the first tissue-engaging element in tissue selectedfrom the group consisting of: tissue of an annulus of anatrioventricular valve, and tissue of a wall of the atrium adjacent theatrioventricular valve. For some applications, the first tissue-engagingelement includes a helical tissue anchor, and implanting the firsttissue-engaging element includes implanting the helical tissue anchor inthe tissue of the atrium. For some applications, implanting the helicaltissue anchor includes screwing the helical tissue anchor into thetissue of the atrium using a torque-delivering tool.

For some applications, the second tissue-engaging element includes aradially-expandable stent, and implanting the second tissue-engagingelement including expanding the radially-expandable in a blood vessel ofthe patient selected from the group consisting of: an inferior venacava, and a superior vena cava.

For some applications:

the first tissue-engaging element includes a helical tissue anchor, andthe second tissue-engaging element includes a radially-expandable stent,

implanting the first tissue-engaging element includes implanting thehelical tissue anchor in tissue selected from the group consisting of:tissue of an annulus of an atrioventricular valve, and tissue of a wallof the atrium adjacent the atrioventricular valve, and

implanting the second tissue-engaging element including expanding theradially-expandable in a blood vessel of the patient selected from thegroup consisting of: an inferior vena cava, a superior vena cava, and acoronary sinus.

For some applications, the method further includes facilitating repairof an atrioventricular valve of the patient by applying tension to thesecond flexible longitudinal member. For some applications, facilitatingrepair includes remodeling the atrioventricular valve by drawingtogether leaflets of the valve by applying tension to the secondflexible longitudinal member.

For some applications, the method further includes decoupling theflexible longitudinal guide member from the firstflexible-longitudinal-member-coupling element, after coupling togetherthe first and the second flexible-longitudinal-member-coupling elements.For some applications:

a proximal end of the first flexible-longitudinal-member-couplingelement is shaped so as to define a threaded coupling,

the flexible longitudinal guide member is shaped so as to define a screwthat is reversibly coupled to the threaded coupling, and

decoupling includes unscrewing the flexible longitudinal guide memberfrom the first flexible-longitudinal-member-coupling element.

For some applications, the flexible longitudinal guide member isreversibly coupled to the first flexible-longitudinal-member-couplingelement by being looped through a portion of the firstflexible-longitudinal-member-coupling element, and decoupling includesreleasing a first end of the flexible longitudinal guide member, andunlooping the flexible longitudinal guide member from the firstflexible-longitudinal-member-coupling element by pulling a second end ofthe flexible longitudinal guide member.

For some applications, implanting the second tissue-engaging elementincludes implanting the second tissue-engaging element after couplingtogether the first and the second flexible-longitudinal-member-couplingelements.

For some applications, implanting the second tissue-engaging elementincludes implanting the second tissue-engaging element before couplingtogether the first and the second flexible-longitudinal-member-couplingelements. For some applications:

the first flexible-longitudinal-member-coupling element includes aplurality of male couplings, disposed along the firstflexible-longitudinal-member-coupling element at respective, differentlongitudinal sites,

the second flexible-longitudinal-member-coupling element includes afemale coupling configured to receive the male couplings, allowadvancement of the male couplings through the female coupling in a firstdirection, and restrict advancement of the male couplings through thefemale coupling in a second direction opposite the first direction, and

coupling together the first and the secondflexible-longitudinal-member-coupling elements includes tensioning thefirst and the second flexible longitudinal members by pulling one ormore of the male couplings into the female coupling, by performing oneor both of the group of actions consisting of: pulling the flexiblelongitudinal guide member, and pushing the secondflexible-longitudinal-member-coupling element.

For some applications, the male couplings have respective conicalfeatures.

For some applications:

the female coupling (a) includes a hollow cylinder configured to receivethe male couplings, and (b) is shaped so as to define one or more tabsbiased to flex toward a central longitudinal axis of the cylinder,

the male couplings are shaped so as to define respective protrusions,

the protrusions and the one or more tabs are shaped and sized to allowthe advancement of the first flexible-longitudinal-member-couplingelement through the cylinder in the first direction, and to restrict theadvancement of the first flexible-longitudinal-member-coupling elementin the second direction, and

coupling together the first and the secondflexible-longitudinal-member-coupling elements includes tensioning thefirst and the second flexible longitudinal members by pulling one ormore of the protrusions through the hollow cylinder, by performing oneor both of the group of actions consisting of: pulling the flexiblelongitudinal guide member, and pushing the secondflexible-longitudinal-member-coupling element.

For some applications, each of the male couplings is shaped so as todefine one or more internal ridges, which are configured to engage theone or more tabs when the tabs enter one of the male couplings.

For some applications, the first flexible-longitudinal-member-couplingelement includes a flexible chain of interconnected links, which areshaped so as to define the male couplings, respectively. For someapplications, the male couplings have respective conical features. Forsome applications, the links are shaped so as to define respectivespherical heads and spherical receptacles, which are shaped and sized soas to couplingly receive the spherical head of an adjacent one of thelinks.

For some applications, the first flexible-longitudinal-member-couplingelement includes a flexible cable to which the male couplings are fixedat the respective, different longitudinal sites. For some applications,the male couplings have respective conical features. For someapplications, the flexible cable is substantially not twistable.

For some applications:

the first flexible-longitudinal-member-coupling element includes (a) acable, which is configured to be flexible and substantially nottwistable; and (b) a wire, which is helically wound around and fixed tothe cable,

the second flexible-longitudinal-member-coupling element includes afemale coupling, which (a) includes a cylinder configured to receive theflexible-longitudinal-member-coupling element, and (b) is shaped so asto define an internal thread shaped and sized so as to correspond withthe helically-wound wire, and

coupling together the first and the secondflexible-longitudinal-member-coupling elements includes tensioning thefirst and the second flexible longitudinal members by rotating the cablewith respect to the female coupling.

For some applications, the wire is helically wound around the cable atan average pitch equal to between one and four times a diameter of thecable.

For some applications, rotating the cable with respect to the femalecoupling includes rotating the flexible longitudinal guide member. Forsome applications, rotating the cable with respect to the femalecoupling includes: advancing a rotation-stabilization tube over theflexible longitudinal guide member; reversibly engaging and rotationallylocking the rotation-stabilization tube with the secondflexible-longitudinal-member-coupling element; and while holding therotation-stabilization tube rotationally stationary, rotating theflexible longitudinal guide member.

For some applications:

the first flexible-longitudinal-member-coupling element includes aflexible cable, the second flexible-longitudinal-member-coupling elementincludes a female coupling, which (a) includes a cylinder configured toreceive the cable, and (b) is shaped so as to define one or more tabsbiased to flex toward a central longitudinal axis of the cylinder,

the cable and the one or more tabs are shaped and sized to allowadvancement of the first flexible-longitudinal-member-coupling elementthrough the cylinder in a first direction, and to restrict, by friction,advancement of the first flexible-longitudinal-member-coupling elementin a second direction opposite the first direction, and

coupling together the first and the secondflexible-longitudinal-member-coupling elements includes tensioning thefirst and the second flexible longitudinal members by performing one orboth of the group of actions consisting of: pulling the flexiblelongitudinal guide member, and pushing the secondflexible-longitudinal-member-coupling element.

For some applications:

the second tissue-engaging element includes a radially-expandable stent,

implanting the second tissue-engaging element including expanding theradially-expandable in a blood vessel of the patient selected from thegroup consisting of: an inferior vena cava, and a superior vena cava,and

advancing the second flexible-longitudinal-member-coupling elementincludes advancing the second flexible-longitudinal-member-couplingelement through the radially-expanded stent.

For some applications, the second flexible-longitudinal-member-couplingelement is shaped so as to define a lumen therethrough, and advancingincludes sliding the second flexible-longitudinal-member-couplingelement along the flexible longitudinal guide member while the flexiblelongitudinal guide member passes through the lumen.

For some applications, the second flexible-longitudinal-member-couplingelement is shaped so as to define a coupling interface that is notcoaxial with the second flexible-longitudinal-member-coupling element,and the second flexible longitudinal member is fixed to the couplinginterface.

For some applications, the method further includes extracting of aportion of the flexible longitudinal guide member to outside a body ofthe patient by snaring the flexible longitudinal guide member. For someapplications:

implanting the first tissue-engaging element includes advancing thefirst tissue-engaging element, the first flexible longitudinal member,and the first flexible-longitudinal-member-coupling element into theatrium via a vein selected from the group of veins consisting of: asuperior vena cava, and an inferior vena cava,

advancing the second tissue-engaging element includes advancing thesecond tissue-engaging element, the second flexible longitudinal member,and the second flexible-longitudinal-member-coupling element into theatrium via the other vein of the group of veins, and

extracting includes extracting of the portion of the flexiblelongitudinal guide member to outside the body via the other vein of thegroup of veins.

For some applications, the method further includes:

implanting the first tissue-engaging element including using a firstdelivery tool, which includes a first catheter tube, to deliver thefirst tissue-engaging element, the first flexible longitudinal member,the first flexible-longitudinal-member-coupling element, and theflexible longitudinal guide member, and

advancing the second flexible-longitudinal-member-coupling element andcoupling together the first and the secondflexible-longitudinal-member-coupling elements includes using a seconddelivery tool, which includes a second catheter tube, to deliver thesecond flexible longitudinal member and the secondflexible-longitudinal-member-coupling element, and to couple the secondflexible-longitudinal-member-coupling element to the firstflexible-longitudinal-member-coupling element.

For some applications:

the second tissue-engaging element includes a radially-expandable stent,

implanting the second tissue-engaging element including expanding theradially-expandable in a blood vessel of the patient selected from thegroup consisting of: an inferior vena cava, and a superior vena cava,and

using the second delivery tool includes passing a portion of the seconddelivery tool through the radially-expanded stent.

For some applications, the second delivery tool further includes anadvancement tube, and coupling together the first and the secondflexible-longitudinal-member-coupling elements includes advancing theadvancement tube through a lumen of the second catheter tube, and usingthe advancement tube to couple the secondflexible-longitudinal-member-coupling element to the firstflexible-longitudinal-member-coupling element.

For some applications:

the first flexible-longitudinal-member-coupling element includes a malecoupling,

the second flexible-longitudinal-member-coupling element includes afemale coupling configured to receive the male coupling, and

coupling together the first and the secondflexible-longitudinal-member-coupling elements includes coupling themale and the female couplings together.

For some applications:

the female coupling (a) includes a cylinder configured to receive themale coupling, (b) is shaped so as to define one or more tabs biased toflex toward a central longitudinal axis of the cylinder,

the male coupling is shaped so as to provide one or more protrusions,and

the male coupling and the one or more tabs are sized and shaped to (a)allow advancement of the male coupling with respect to the one or moretabs in a first direction, by pushing the one or more tabs away from thelongitudinal axis, and (b) restrict advancement of the male couplingwith respect to the one or more tabs in a second direction opposite thefirst direction.

For some applications, the male coupling is shaped so as to define oneor more internal ridges, which are configured to engage the one or moretabs when the tabs enter the male coupling.

For some applications, the one or more protrusions are shaped so as todefine a shelf, and the one or more tabs are configured to flex towardthe longitudinal axis after the advancement of the shelf of the malecoupling beyond the one or more tabs, so as to restrict advancement ofthe male coupling with respect to the one or more tabs in the seconddirection.

For some applications:

the female coupling includes a structural element including one or morewalls shaped so as to define an opening,

the male coupling includes one or more radially-displaceable arms, andthe one or more radially-displaceable arms are:

-   -   compressible by the walls during advancement of the one or more        radially-displaceable arms through the opening, and    -   following advancement of the one or more radially-displaceable        arms through opening, expandable to a first dimension that is        larger than a second dimension of the opening so as to lock the        male coupling to the female coupling.

For some applications:

the female coupling includes a structural element including one or morewalls shaped so as to define an opening,

the male coupling includes one or more radially-displaceable arms, and

the one or more radially-displaceable arms are:

-   -   compressible by the walls during advancement of the one or more        radially-displaceable arms through the opening, and    -   following advancement of the one or more radially-displaceable        arms through opening, expandable to a position in which at least        a portion of an outer surface of the one or more arms is beyond        and above the one or more walls.

For some applications:

the female coupling includes a structural element including one or morewalls shaped so as to define one or more shelves,

the male coupling includes one or more radially-displaceable legs, and

the one or more radially-displaceable legs are:

-   -   compressible by the walls during advancement of the one or more        radially-displaceable legs along the one or more shelves, and    -   following the advancement of the one or more        radially-displaceable legs beyond the one or more shelves in a        first advancement direction, expandable to lock the male        coupling to the female coupling, and

following expanding of the one or more radially-displaceable legs, theone or more shelves of the female coupling restrict advancement of theone or more radially-displaceable legs in a second advancement directionopposite the first advancement direction.

For some applications, the one or more walls of the female couplingelement are shaped so as to define at least one groove, and the malecoupling element is shaped so as to define at least one protrusionshaped so as to fit within the at least one groove.

For some applications, the female coupling includes a structural elementshaped so as to define a curved groove, and the male coupling includes aprojection advanceable within the curved groove so as to lock the malecoupling to the female coupling.

There is additionally provided, in accordance with an application of thepresent invention, apparatus including:

a stent;

a longitudinal member, which has a distal end that includes an annularloop that extends laterally from the longitudinal member; and

a tissue anchor, which is coupled to the annular loop, such that theanchor can rotate with respect to the annular loop, the longitudinalmember, and the stent.

There is also provided, in accordance with some applications of thepresent invention, apparatus, including:

a radially-expandable percutaneous implant;

a tissue anchor having a central longitudinal axis;

a connecting element shaped so as to provide an annular loop surroundinga proximal portion of the tissue anchor in a manner which enablesrotation of the anchor about the central longitudinal axis whensurrounded by the annular loop; and

a flexible longitudinal member coupled at a first portion thereof to atleast a portion of the percutaneous implant and at a second portion tothe connecting element, the annular loop of the connecting elementfacilitating rotation of the tissue anchor about the centrallongitudinal axis such that the anchor can rotate about the centrallongitudinal axis with respect to the annular loop, the flexiblelongitudinal member, and the percutaneous implant.

In some applications of the present invention, the longitudinal memberincludes a plurality of fibers.

In some applications of the present invention, the plurality of fibersare arranged such that the longitudinal member has a length of between10 mm and 300 mm, a width of between 1 and 4 mm, and a thickness ofbetween 1 and 2 mm.

In some applications of the present invention, the plurality of fibersare arranged such that the longitudinal member has a length of between20 mm and 80 mm, a width of between 1 and 4 mm, and a thickness ofbetween 1 and 2 mm.

In some applications of the present invention, the plurality of fibersare interwoven so as to form a fabric.

In some applications of the present invention, the apparatus includes:

a tube, which is sized to pass through a lumen defined by thepercutaneous implant, the tube having at least one tube lumen, and atorque-delivering tool configured for slidable passage through the tube,the torque-delivering tool is configured to be removably coupled to thetissue anchor, such that rotation of the torque-delivering tool rotatesthe tissue anchor.

In some applications of the present invention, the apparatus includes asheath configured to surround the percutaneous implant such that thepercutaneous implant is maintained in a crimped state when the sheathsurrounds the implant, and the sheath is slidable with respect to thetube in order to expose the implant from within the sheath.

In some applications of the present invention, the apparatus includes asecondary tube through which a guidewire may be passed, the secondarytube being configured to be disposed alongside the tube surrounding thetorque-delivering tool, the guidewire being configured to facilitateguiding of the apparatus through vasculature of a patient.

In some applications of the present invention:

the connecting element is shaped so as to define aflexible-longitudinal-member-coupler at a proximal portion thereof thatis proximal to the annular loop,

the flexible-longitudinal-member-coupler is coupled to the secondportion of the flexible longitudinal member, and

the torque-delivering tool passes alongside the flexible longitudinalmember in a manner which restricts entanglement of the flexiblelongitudinal member during rotation of the torque-delivering tool torotate the anchor.

In some applications of the present invention, the apparatus includes ananti-entanglement device coupled to the tube at a distal portionthereof, the anti-entanglement device is configured to restrictentanglement of the flexible longitudinal member during (1) rotation ofthe torque-delivering tool to rotate the anchor, and (2) rotation of theanchor with respect to the surrounding annular loop of the connectingelement.

In some applications of the present invention, the anti-entanglementdevice is configured to be disposed adjacently to theflexible-longitudinal-member-coupler in a manner which restrictsentanglement of the flexible longitudinal member during rotation of thetorque-delivering tool to rotate the anchor.

In some applications of the present invention, the apparatus includes:

the torque-delivering tool includes a first coupling at a distal endthereof, and

the apparatus further includes an adapter head coupled to the tissueanchor at a proximal end of the tissue anchor, the adapter headincluding a second coupling reversibly couplable to the first couplingin a manner which:

-   -   (1) couples the tissue anchor to the torque-delivering tool when        the first and second couplings are coupled together, and    -   (2) decouples the tissue anchor from the torque-delivering tool        when the first and second couplings are not coupled together.

In some applications of the present invention, the first couplingincludes a male coupling, the second coupling includes a femalecoupling, and the first and second couplings are couplable together bybeing matingly engaged.

In some applications of the present invention, when the distal end ofthe tool is surrounded by the tube, the first and second couplings aredisposed within the tube and are engaged, and the tool is slidablewithin the tube so as to expose the distal end of the tool and the firstand second couplings from within the tube in order to facilitatedisengaging of the couplings.

In some applications of the present invention, the apparatus includes aproximal handle portion coupled to a proximal portion of the tube, thehandle portion including:

a holder having a recess, the holder being coupled to a proximal portionof the tube, and

an anchor-deployment actuator including a proximal knob and a distalprotrusion slidable within the recess of the holder, wherein:

-   -   the anchor-deployment actuator is coupled to a proximal portion        of the torque-delivering tool,    -   the torque-delivering tool is slidable within the tube,    -   the anchor-deployment actuator is rotatable to rotate the        torque-delivering tool and the anchor, and    -   during a pushed state of the anchor-deployment actuator, the        protrusion slides distally within the recess of the holder, and        responsively, the torque-delivering tool is pushed distally to        expose the first and second couplings from within the tube and        disengage the first and second couplings.

In some applications of the present invention, the apparatus includes asafety coupled to the holder configured to prevent unwanted slidingdistally of the protrusion of the anchor-deployment actuator within therecess of the holder.

In some applications of the present invention, at least a proximalportion of the tissue anchor is shaped so as to define an opening and apassage therethrough, and the adapter head is shaped so as to define adistal protrusion sized so as to fit within the passage, therebycoupling the adapter head to the tissue anchor.

In some applications of the present invention:

a portion of the adapter head that is between the distal protrusion andthe second coupling is shaped so as to define a longest dimension at afirst cross-sectional plane that is perpendicular to the central axis ofthe tissue anchor,

the annular loop of the connecting element is shaped so as to define alongest dimension a second cross-sectional plane that is perpendicularto the central axis of the tissue anchor, and

the proximal portion of the adapter head is disposed coaxiallyproximally to the annular loop along the longitudinal axis in a mannerwhich restricts decoupling of the connecting element from the tissueanchor.

In some applications of the present invention, the percutaneous implantis shaped so as to define a tension-distributing element, and the firstportion of the flexible longitudinal element is coupled to thepercutaneous implant via the tension-distributing element.

In some applications of the present invention, the tension-distributingelement and the percutaneous implant are fabricated from a single unit.

In some applications of the present invention, the tension-distributingelement is configured to distribute tension applied by the flexiblelongitudinal member along a longitudinal length of the percutaneousimplant.

In some applications of the present invention, the tension-distributingelement has a width of between 1 and 4 mm.

In some applications of the present invention, the percutaneous implantincludes a stent including a plurality of struts, and a width of awidest strut is between 100 and 500 micron, and a width of thetension-distributing element is between 1 and 4 mm.

In some applications of the present invention, the percutaneous implantincludes an endoluminal implant including a stent including a pluralityof struts, and a width of the tension-distributing element is at least13 times a width of a widest strut of the stent.

In some applications of the present invention, a longitudinal length ofthe tension-distributing element is at least 15% of the longitudinallength of the percutaneous implant.

In some applications of the present invention, the longitudinal lengthof the percutaneous implant is between 20 and 120 mm, and thelongitudinal length of the tension-distributing element is between 10and 120 mm.

In some applications of the present invention, the percutaneous implantincludes an endoluminal implant including a stent.

In some applications of the present invention, a first section of thestent includes two or more coaxial annular ring portions, each ringportion shaped so as to define a plurality of peaks and valleys, and thefirst section includes a plurality of interconnectors configured toconnect the two or more annular ring portions.

In some applications of the present invention:

the two or more coaxial annular ring portions include first and secondannular ring portions that are in phase, and

each one of the plurality of interconnectors is disposed verticallybetween a respective valley of the first and second ring portions.

In some applications of the present invention:

the stent is configured to assume a compressed state within a sheath andan expanded state when exposed from within the sheath by retracting thesheath in a distal-to-proximal direction,

each one of the valleys of the first annular ring portion is connectedby a respective interconnector to a respective valley of the secondannular ring portion, and

each one of the peaks points in a distal direction in a manner in which,following expansion of the first and second annular ring portions fromwithin a sheath, the first and second annular ring portions arecompressible and retrievable into the sheath when the sheath is advancedin a proximal-to-distal direction.

In some applications of the present invention, the stent is shaped so asto define a first section configured, in a radially-expanded state ofthe stent, to exert a stronger radial force on surrounding tissue than asecond section of the stent.

In some applications of the present invention, the first and secondportions are each shaped so as to define respective wire structures,each wire structure including a respective plurality of wire segments,and each wire segment of the second portion has a length greater than alength of a respective wire segment of the first portion.

In some applications of the present invention, the first and secondportions are each shaped so as to define respective wire structures,each wire structure including a respective plurality of wire segments,and each wire segment of the first portion has a thickness greater thana thickness of a respective wire segment of the second portion.

In some applications of the present invention, each wire segment of thefirst portion has a thickness of between 50 and 1000 micron, and eachwire segment of the second portion has a thickness of between 50 and1000 micron.

In some applications of the present invention, the first sectionincludes two or more coaxial annular ring portions, each ring portionshaped so as to define a plurality of peak and valleys, and the firstsection includes a plurality of interconnectors configured to connectthe two or more annular ring portions.

In some applications of the present invention:

the two or more coaxial annular ring portions include first and secondannular ring portions that are in phase, and

each one of the plurality of interconnectors is disposed verticallybetween a respective valley of the first and second ring portions.

In some applications of the present invention:

the stent is configured to assume a compressed state within a sheath andan expanded state when exposed from within the sheath by retracting thesheath in a distal-to-proximal direction,

each one of the valleys of the first annular ring portion is connectedby a respective interconnector to a respective valley of the secondannular ring portion, and

each one of the peaks points in a distal direction in a manner in which,following expansion of the first and second annular ring portions fromwithin a sheath, the first and second annular ring portions arecompressible and retrievable into the sheath when the sheath is advancedin a proximal-to-distal direction.

In some applications of the present invention, the second sectionincludes a plurality of vertical elements extending from the firstportion.

In some applications of the present invention, the vertical elementseach have a length of between 10 and 80 mm.

In some applications of the present invention, the stent is shaped so asto define a third portion configured, in the radially-expanded state ofthe stent, to exert a stronger radial force on surrounding tissue thanthe second section of the stent.

There is further provided, in accordance with some applications of thepresent invention, a method, including:

providing (a) a radially-expandable percutaneous implant, (b) tissueanchor having a central longitudinal axis, (c) a connecting elementshaped so as to provide an annular loop surrounding a proximal portionof the tissue anchor in a manner which enables rotation of the anchorabout the central longitudinal axis when surrounded by the annular ring,and (d) a flexible longitudinal member, which has a first portion thatis coupled to at least a portion of the percutaneous implant and asecond portion that is coupled to the connecting element;

positioning the percutaneous implant in a blood vessel of a patient;

coupling the tissue anchor to tissue in a vicinity of a heart valve ofthe patient by rotating the anchor with respect to the annular loop, thelongitudinal member, and the percutaneous implant; and

after coupling the tissue anchor to the tissue, deploying thepercutaneous implant such that the implant expands and is implanted inthe blood vessel at an implantation site.

In some applications of the present invention, the method includes,after coupling the tissue anchor to the tissue and before deploying thepercutaneous implant, pulling the anchor toward the implantation site.

In some applications of the present invention, the blood vessel isselected from the group of blood vessels consisting of: a superior venacava, an inferior vena cava, a coronary sinus, and a hepatic vein.

In some applications of the present invention, rotating includesrotating the anchor using a tube, which passes through a lumen definedby the stent, and which is removably coupled to the tissue anchor.

There is additionally provided, in accordance with some applications ofthe present invention, a method, including:

providing (a) a radially-expandable percutaneous implant, (b) tissueanchor having a central longitudinal axis, (c) a connecting elementshaped so as to provide an annular loop surrounding a proximal portionof the tissue anchor in a manner which enables rotation of the anchorabout the central longitudinal axis when surrounded by the annular ring,and (d) a flexible longitudinal member, which has a first portion thatis coupled to at least a portion of the percutaneous implant and asecond portion that is coupled to the connecting element; and

rotating the anchor with respect to the annular loop, the longitudinalmember, and the percutaneous implant while restricting rotation of theflexible longitudinal member.

There is yet additionally provided, in accordance with some applicationsof the present invention, apparatus including:

a radially-expandable percutaneous implant shaped so as to define atension-distributing element; and

a flexible longitudinal member coupled at a first portion thereof to atleast a portion of the percutaneous implant via the tension-distributingelement, and the tension-distributing element is configured todistribute tension applied by the flexible longitudinal member along alongitudinal length of the percutaneous implant.

In some applications of the present invention, the apparatus includes atissue anchor coupled to the flexible longitudinal member at a secondportion thereof, the tissue anchor, and the flexible longitudinal memberbeing configured to apply tension to the tension-distributing element.

In some applications of the present invention, the tension-distributingelement and the percutaneous implant are fabricated from a single unit.

In some applications of the present invention, the tension-distributingelement has a width of between 1 and 4 mm.

In some applications of the present invention, the percutaneous implantincludes a stent including a plurality of struts, and a width of awidest strut is between 100 and 500 micron and a width of thetension-distributing element is between 1 and 4 mm.

In some applications of the present invention, the percutaneous implantincludes a stent including a plurality of struts, and a width of thetension-distributing element is at least 13 times a width of a wideststrut of the stent.

In some applications of the present invention, a longitudinal length ofthe tension-distributing element is at least 15% of the longitudinallength of the percutaneous implant.

In some applications of the present invention, the longitudinal lengthof the percutaneous implant is between 20 and 120 mm, and thelongitudinal length of the tension-distributing element is between 10and 120 mm.

In some applications of the present invention, the percutaneous implantincludes an endoluminal implant including a stent.

In some applications of the present invention, a first section of thestent includes two or more coaxial annular ring portions, each ringportion shaped so as to define a plurality of peaks and valleys, and thefirst section includes a plurality of interconnectors configured toconnect the two or more annular ring portions.

In some applications of the present invention:

the two or more coaxial annular ring portions include first and secondannular ring portions that are in phase, and

each one of the plurality of interconnectors is disposed verticallybetween a respective valley of the first and second ring portions.

In some applications of the present invention:

the stent is configured to assume a compressed state within a sheath andan expanded state when exposed from within the sheath by retracting thesheath in a distal-to-proximal direction,

each one of the valleys of the first annular ring portion is connectedby a respective interconnector to a respective valley of the secondannular ring portion, and

each one of the peaks points in a distal direction in a manner in which,following expansion of the first and second annular ring portions fromwithin a sheath, the first and second annular ring portions arecompressible and retrievable into the sheath when the sheath is advancedin a proximal-to-distal direction.

In some applications of the present invention, the stent is shaped so asto define a first section configured to exert a stronger radial force onsurrounding tissue than a second section of the stent.

In some applications of the present invention, the first and secondportions are each shaped so as to define respective wire structures,each wire structure including a respective plurality of wire segments,each wire segment of the second portion has a length greater than alength of a respective wire segment of the first portion.

In some applications of the present invention, the first and secondportions are each shaped so as to define respective wire structures,each wire structure including a respective plurality of wire segments,each wire segment of the first portion has a thickness greater than athickness of a respective wire segment of the second portion.

In some applications of the present invention, each wire segment of thefirst portion has a thickness of between 100 and 1000 micron, and eachwire segment of the second portion has a thickness of between 100 and1000 micron.

In some applications of the present invention, the first sectionincludes two or more coaxial annular ring portions, each ring portionshaped so as to define a plurality of peak and valleys, and the firstsection includes a plurality of interconnectors configured to connectthe two or more annular ring portions.

In some applications of the present invention:

the two or more coaxial annular ring portions include first and secondannular ring portions that are in phase,

each one of the plurality of interconnectors is disposed verticallybetween a respective valley of the first and second ring portions.

In some applications of the present invention:

the stent is configured to assume a compressed state within a sheath andan expanded state when exposed from within the sheath by retracting thesheath in a distal-to-proximal direction,

each one of the valleys of the first annular ring portion is connectedby a respective interconnector to a respective valley of the secondannular ring portion, and

each one of the peaks points in a distal direction in a manner in which,following expansion of the first and second annular ring portions fromwithin a sheath, the first and second annular ring portions arecompressible and retrievable into the sheath when the sheath is advancedin a proximal-to-distal direction.

In some applications of the present invention, the second sectionincludes a plurality of vertical elements extending from the firstportion.

In some applications of the present invention, the vertical elementseach have a length of between 10 and 60 mm.

In some applications of the present invention, the stent is shaped so asto define a third portion configured to exert a stronger radial force onsurrounding tissue than the second section of the stent.

There is also provided, in accordance with some applications of thepresent invention, apparatus, including:

a first radially-expandable percutaneous implant including a pluralityof mechanical structural elements arranged so as to assume a firsttubular structure, the first radially-expandable percutaneous implant,in a radially-expanded state thereof, having a lumen having an innerdiameter;

a flexible longitudinal member coupled at a first portion thereof to atleast a portion of the first radially-expandable percutaneous implant,the flexible longitudinal member being configured to apply tension tothe first radially-expandable percutaneous implant; and

a second radially-expandable percutaneous implant positionable withinthe lumen of the first radially-expandable percutaneous implant, thesecond radially-expandable percutaneous implant:

including a plurality of mechanical structural elements arranged so asto assume a second tubular structure,

being shaped so as to define a plurality of tissue-engaging elementsconfigured to engage tissue of a patient in a radially-expanded state ofthe second radially-expandable percutaneous implant,

in the radially-expanded state thereof, being configured to:

-   -   excluding the plurality of tissue-engaging elements, assume an        outer diameter of the second radially-expandable percutaneous        implant that is at least as large as the inner diameter of the        first radially-expandable percutaneous implant in the        radially-expanded state of the first radially-expandable        percutaneous implant, and    -   provide anchoring of the first radially-expandable percutaneous        implant in the radially-expanded state, to tissue of the patient        by facilitating engaging of the plurality of tissue-engaging        elements with the tissue of the patient in the radially-expanded        state of the second radially-expandable percutaneous implant.

In some applications of the present invention, the apparatus includes atissue anchor coupled to the flexible longitudinal member at a secondportion thereof, the tissue anchor, and the flexible longitudinal memberbeing configured to apply tension to the tension-distributing element.

In some applications of the present invention, the plurality oftissue-engaging elements include a plurality of barbs.

In some applications of the present invention, in the radially-expandedstate of the second radially-expandable percutaneous implant, the secondradially-expandable percutaneous implant pushes radially against thefirst radially-expandable percutaneous implant.

There is further provided, in accordance with some applications of thepresent invention, a method, including:

positioning a first radially-expandable percutaneous implant in a bloodvessel of a patient, the first radially-expandable percutaneous implantincluding a plurality of mechanical struts arranged so as to assume afirst tubular structure, the first radially-expandable percutaneousimplant, in a radially-expanded state thereof, having a lumen having aninner diameter,

applying tension to the first radially-expandable percutaneous implant;

while tension is applied to the first radially-expandable percutaneousimplant, expanding the first radially-expandable percutaneous implant inthe blood vessel in a manner in which the first radially-expandablepercutaneous implant exerts a radial force on the blood vessel; and

anchoring the first radially-expandable percutaneous implant to theblood vessel by expanding a second radially-expandable percutaneousimplant within the lumen of the first radially-expandable percutaneousimplant, the second radially-expandable percutaneous implant including aplurality of mechanical struts arranged so as to assume a second tubularstructure, and by the expanding, engaging a plurality of tissue-engagingelements of the second radially-expandable percutaneous implant withtissue of the blood vessel.

In some applications of the present invention, expanding the secondradially-expandable percutaneous implant includes expanding the secondradially-expandable percutaneous implant in a manner in which the secondradially-expandable percutaneous implant, excluding the plurality oftissue-engaging elements, assumes an outer diameter that is at least aslarge as the inner diameter of the first radially-expandablepercutaneous implant in the radially-expanded state of the firstradially-expandable percutaneous implant.

In some applications of the present invention, prior to expanding thesecond radially-expandable percutaneous implant, allowing migrationwithin the blood vessel of the first radially-expandable percutaneousimplant.

In some applications of the present invention, engaging the plurality oftissue-engaging elements of the second radially-expandable percutaneousimplant with tissue of the blood vessel includes preventing migration ofthe first radially-expandable implant within the blood vessel.

There is additionally provided, in accordance with some applications ofthe present invention, apparatus, including:

a first tissue-engaging element;

a first flexible longitudinal member coupled at a first end portionthereof to at least a portion of the first tissue-engaging element;

a first flexible-longitudinal-member-coupling element coupled to thefirst flexible longitudinal member at a second end portion of the firstflexible longitudinal member;

a second tissue-engaging element;

a second flexible longitudinal member coupled at a first end portionthereof to at least a portion of the second tissue-engaging element; and

a second flexible-longitudinal-member-coupling element coupled to thesecond flexible longitudinal member at a second end portion of thesecond flexible longitudinal member, the first and secondflexible-longitudinal-member-coupling elements being couplable to coupletogether the first and second flexible longitudinal elements.

In some applications of the present invention, at least a portion of thefirst tissue-engaging element is shaped so as to define a loop, and thefirst end portion of the first flexible longitudinal member isconfigured to be looped at least in part around the loop of the firsttissue-engaging element.

In some applications of the present invention, the apparatus includes aconnecting element coupled to the first tissue-engaging element, theconnecting element shaped so as to provide an annular loop surrounding aproximal portion of the first tissue-engaging element in a manner whichenables rotation of the anchor about the central longitudinal axis whensurrounded by the annular loop, wherein the annular loop of theconnecting element facilitates rotation of the first tissue-engagingelement about a central longitudinal axis of the first tissue-engagingelement such that the first tissue-engaging element can rotate about thecentral longitudinal axis with respect to the annular loop and the firstflexible longitudinal member.

In some applications of the present invention, the apparatus includes aflexible-longitudinal-member-adjustment mechanism coupled to a flexiblelongitudinal member selected from the group consisting of: the firstflexible longitudinal member and the second flexible longitudinalmember, and the flexible-longitudinal-member-adjustment mechanism isconfigured to adjust a length of the selected flexible longitudinalmember.

In some applications of the present invention, theflexible-longitudinal-member-adjustment mechanism includes a spoolconfigured to adjust a length of the selected flexible longitudinalmember by winding a portion of the selected flexible longitudinal memberaround the spool.

In some applications of the present invention, the first tissue-engagingelement includes a tissue anchor configured to penetrate tissue of anannulus of an atrioventricular valve of a patient.

In some applications of the present invention, the secondtissue-engaging element includes a radially-expandable percutaneousimplant configured to engage tissue of the patient upstream of theatrioventricular valve.

In some applications of the present invention, the radially-expandablepercutaneous implant includes a stent configured for placement within ablood vessel that empties into an atrium of a heart of the patient.

In some applications of the present invention, the tissue anchorincludes a helical tissue anchor, and the apparatus further includes atorque-delivering tool configured to corkscrew the helical tissue anchorinto tissue of a patient.

In some applications of the present invention, the apparatus includes aconnecting element shaped to define an annular loop surrounding aproximal portion of the tissue anchor, in a manner which enablesrotation of the anchor about a longitudinal axis of the tissue anchor,when surrounded by the annular loop, and with respect to the firstflexible longitudinal member.

In some applications of the present invention:

the apparatus further includes a first coupling element coupled to thefirst tissue-engaging element, the first coupling element having afirst-coupling-element longitudinal axis and shaped so as to define:

-   -   a first-coupling-element main body portion shaped so as to        define a first-coupling-element-main-body passage,    -   a first-coupling-element secondary body portion coaxial with the        first-coupling-element main body portion, the first-coupling        element secondary body portion shaped so as to define a        first-coupling-element-secondary-body-portion passage coaxial        with the first-coupling-element-main-body passage; and    -   a connecting element connecting the first-coupling-element        secondary body portion to the first-coupling-element main body        portion,

the first coupling element is shaped so as to define afirst-coupling-element space between the first-coupling-element mainbody portion and the first-coupling-element secondary body portion,

the apparatus further includes a second coupling element having asecond-coupling-element longitudinal axis and shaped so as to define:

-   -   a second-coupling-element main body portion shaped so as to        define second-coupling-element-main-body passage,    -   a second-coupling-element secondary body portion coaxial with        the main body portion, the second-coupling-element secondary        body portion shaped so as to define a        second-coupling-element-secondary-body-portion passage coaxial        with the second-coupling-element-main-body passage, and    -   a connecting element connecting the second-coupling-element        secondary body portion to the second-coupling-element main body        portion,

the second coupling element is shaped so as to define asecond-coupling-element space between the main body portion and thesecondary body portion, and

the first and second coupling elements are couplable together by fittingthe first-coupling-element secondary body portion within thesecond-coupling-element space of the second coupling element, and byfitting the second-coupling-element secondary body portion within thefirst-coupling-element space of the first coupling element in a mannerin which the first-coupling-element-main-body passage, thefirst-coupling-element-secondary-body-portion passage, thesecond-coupling-element-main-body passage, and thesecond-coupling-element-secondary-body-portion passage are aligned, and

the apparatus further includes an elongate longitudinal element:

-   -   disposable within the first-coupling-element-main-body passage,        the first-coupling-element-secondary-body-portion passage, the        second-coupling-element-main-body passage, and the        second-coupling-element-secondary-body-portion passage to        maintain coupling of the first coupling element to the second        coupling element, and    -   removable from the first-coupling-element-main-body passage, the        first-coupling-element-secondary-body-portion passage, the        second-coupling-element-main-body passage, and the        second-coupling-element-secondary-body-portion passage to        facilitate decoupling of the first and second coupling elements.

In some applications of the present invention, the elongate longitudinalelement includes a rod.

In some applications of the present invention, thefirst-coupling-element main body portion is shaped so as to define acylinder.

In some applications of the present invention, thesecond-coupling-element main body portion is shaped so as to define acylinder.

In some applications of the present invention, the firstflexible-longitudinal-member-coupling element includes a male coupling,and the second flexible-longitudinal-member-coupling element includes afemale coupling configured to receive the male coupling.

In some applications of the present invention, the female coupling isshaped so as to define one or more grooves, and the male coupling isshaped so as to provide one or more protrusions configured to fit withinthe one or more grooves of the female coupling.

In some applications of the present invention:

the female coupling includes a cylinder configured to receive the malecoupling,

the female coupling is shaped so as to define one or more tabs biased toflex toward a longitudinal axis of the cylinder,

the male coupling is shaped so as to provide one or more protrusionsdefining a shelf,

the male coupling advanceable with respect to the one or more tabs in afirst direction to push the tab away from the longitudinal axis, and

the one or more tabs are configured to flex toward the longitudinal axisafter the advancement of the shelf of the male coupling beyond the oneor more tabs to restrict advancement of the male coupling in a seconddirection.

In some applications of the present invention,

the female coupling includes a structural element including one or morewalls shaped so as to define an opening,

the male coupling includes one or more radially-displaceable arms, and

the one or more radially-displaceable arms are:

-   -   compressible by the walls during advancement of the one or more        radially-displaceable arms through the opening, and    -   following advancement of the one or more radially-displaceable        arms through the opening, expandable to a first dimension that        is larger than a second dimension of the opening so as to lock        the male coupling to the female coupling.

In some applications of the present invention,

the female coupling includes a structural element including one or morewalls shaped so as to define an opening,

the male coupling includes one or more radially-displaceable arms, and

the one or more radially-displaceable arms are:

-   -   compressible by the walls during advancement of the one or more        radially-displaceable arms through the opening, and    -   following advancement of the one or more radially-displaceable        arms through opening, expandable to a position in which at least        a portion of an outer surface of the one or more arms is beyond        and above the one or more walls.

In some applications of the present invention,

the female coupling includes a structural element including one or morewalls shaped so as to define one or more shelves,

the male coupling includes one or more radially-displaceable legs,

the one or more radially-displaceable legs are:

-   -   compressible by the walls during advancement of the one or more        radially-displaceable legs along the one or more shelves, and    -   following the advancement of the one or more        radially-displaceable legs beyond the one or more shelves in a        first advancement direction, expandable to lock the male        coupling to the female coupling, and

following expanding of the one or more radially-displaceable legs, theone or more shelves of the female coupling restrict advancement of theone or more radially-displaceable legs in a second advancementdirection.

In some applications of the present invention, the one or more walls ofthe female coupling element is shaped so as to define at least onegroove, and the male coupling element is shaped so as to define at leastone protrusion shaped so as to fit within the at least one groove.

In some applications of the present invention, the female couplingincludes a structural element shaped so as to define a curved groove,and the male coupling includes a projection advanceable within thecurved groove so as to lock the male coupling to the female coupling.

In some applications of the present invention, the apparatus furtherincludes a flexible longitudinal guide member reversibly coupled to thefirst flexible-longitudinal-member-coupling element.

In some applications of the present invention, the flexible longitudinalguide member is reversibly coupled to the firstflexible-longitudinal-member-coupling element by being looped through aportion of the first flexible-longitudinal-member-coupling element.

In some applications of the present invention:

the first flexible-longitudinal-member-coupling element is shaped so asto define a first coupling,

the flexible longitudinal guide member is reversibly coupled to thefirst flexible-longitudinal-member-coupling element via the firstcoupling, and

the flexible longitudinal guide member is configured to facilitateadvancement of the second flexible-longitudinal-member-coupling elementalong the guide member and toward the firstflexible-longitudinal-member-coupling element.

In some applications of the present invention, the apparatus includes asnare couplable to the flexible longitudinal guide member so as tofacilitate extraction of a portion of the guide member outside a body ofa patient.

In some applications of the present invention:

the first tissue-engaging element, the first flexible longitudinalmember, and the first flexible-longitudinal-member-coupling element areadvanceable within the body of that patient from a first site thereof,

the second tissue-engaging element, the second flexible longitudinalmember, and the second flexible-longitudinal-member-coupling element areadvanceable within the body of that patient from a second site thereof,and

the snare is configured to extend a portion of the flexible longitudinalguide member toward the second site.

In some applications of the present invention, the first couplingincludes a threaded coupling, and the flexible longitudinal guide memberis reversibly coupled to the first coupling by being screwed withrespect to the threaded coupling.

In some applications of the present invention, the first coupling isshaped so as to define at least one shelf, and the apparatus furtherincludes a longitudinal-guide-member-coupling element, and thelongitudinal-guide-member-coupling element is:

coupled to the longitudinal guide member,

restricted from advancement in a first direction by the at least oneshelf, and

displaceable with respect to the at least one shelf in response to achange in a spatial orientation of thelongitudinal-guide-member-coupling element with respect to the at leastone shelf, and allowed to advance in the first direction in order todecouple the longitudinal guide member from the firstflexible-longitudinal-member-coupling element.

In some applications of the present invention:

the first flexible-longitudinal-member-coupling element has afirst-coupling-element longitudinal axis and the first coupling isshaped so as to define:

-   -   a first-coupling-element main body portion shaped so as to        define first-coupling-element-main-body passage;    -   a first-coupling-element secondary body portion coaxial with the        main body portion, the first-coupling element secondary body        portion shaped so as to define a        first-coupling-element-secondary-body-portion passage coaxial        with the first-coupling-element-main-body passage; and    -   a connecting element connecting the secondary body portion to        the main body portion,

the first flexible-longitudinal-member-coupling element is shaped so asto define a first-coupling-element space between the main body portionand the secondary body portion,

the apparatus further includes a longitudinal-guide-member-couplingelement having a longitudinal-guide-member-coupling element longitudinalaxis and a second coupling, wherein the flexible longitudinal guidemember coupled to the longitudinal-guide-member-coupling element, and isreversibly coupled to the first flexible-longitudinal-member-couplingelement via the longitudinal-guide-member-coupling element, the secondcoupling being shaped so as to define:

-   -   a longitudinal-guide-member-coupling-element main body portion        shaped so as to define second-coupling-element-main-body        passage;    -   a longitudinal-guide-member-coupling-element secondary body        portion coaxial with the main body portion, the        longitudinal-guide-member-coupling-element secondary body        portion shaped so as to define a        longitudinal-guide-member-coupling        element-secondary-body-portion passage coaxial with the        longitudinal-guide-member-coupling-element-main-body passage;        and    -   a connecting element connecting the        longitudinal-guide-member-coupling-element secondary body        portion to the longitudinal-guide-member-coupling-element main        body portion,

the second coupling element is shaped so as to define asecond-coupling-element space between the main body portion and thesecondary body portion, and

the first and second couplings are couplable together by fitting thefirst-coupling-element secondary body portion within thelongitudinal-guide-member-coupling-element space of the second couplingelement, and by fitting the longitudinal-guide-member-coupling-elementsecondary body portion within the first-coupling-element space of thefirst coupling element in a manner in which thefirst-coupling-element-main-body passage, thefirst-coupling-element-secondary-body-portion passage, thelongitudinal-guide-member-coupling-element-main-body passage, and thelongitudinal-guide-member-coupling-element-secondary-body-portionpassage are aligned.

In some applications of the present invention, the apparatus furtherincludes an elongate longitudinal element:

disposable within the first-coupling-element-main-body passage, thefirst-coupling-element-secondary-body-portion passage, thelongitudinal-guide-member-coupling-element-main-body passage, and thelongitudinal-guide-member-coupling-element-secondary-body-portionpassage to maintain coupling of the first and second couplings, and

removable from the first-coupling-element-main-body passage, thefirst-coupling-element-secondary-body-portion passage, thelongitudinal-guide-member-coupling-element-main-body passage, and thelongitudinal-guide-member-coupling-element-secondary-body-portionpassage to facilitate decoupling of the first and second couplings.

There is yet additionally provided, in accordance with some applicationsof the present invention a method, including:

implanting a first tissue-engaging element at a first implantation sitein tissue of an atrioventricular valve of a patient;

extending from the first tissue-engaging element, a first flexiblelongitudinal member coupled at a first end portion thereof to at least aportion of the first tissue-engaging element, the first flexiblelongitudinal element being coupled at a second end portion thereof to afirst flexible-longitudinal-member-coupling element;

advancing toward the valve of the patient a second tissue-engagingelement coupled to a first end portion of a second flexible longitudinalmember, the second flexible longitudinal member being coupled at asecond end portion thereof to a secondflexible-longitudinal-member-coupling element;

coupling together the first and secondflexible-longitudinal-member-coupling elements;

facilitating repairing of the atrioventricular valve by pulling on thesecond tissue-engaging element, and responsively, pulling on the firstand second flexible longitudinal members; and

implanting the second tissue-engaging element at a second implantationsite upstream of the atrioventricular valve.

In some applications of the present invention, facilitating repairingincludes remodeling the atrioventricular valve by drawing togetherleaflets of the valve responsively to the pulling.

There is still yet additionally provided, in accordance with someapplications of the present invention, apparatus including:

a first coupling element having a first-coupling-element longitudinalaxis and shaped so as to define:

-   -   a first-coupling-element main body portion shaped so as to        define first-coupling-element-main-body passage;    -   a first-coupling-element secondary body portion coaxial with the        first-coupling-element main body portion, the first-coupling        element secondary body portion shaped so as to define a        first-coupling-element-secondary-body-portion passage coaxial        with the first-coupling-element-main-body passage; and    -   a first-coupling-element connecting element connecting the        first-coupling-element secondary body portion to the        first-coupling-element main body portion,

wherein the first coupling element is shaped so as to define afirst-coupling-element space between the first-coupling-element mainbody portion and the first-coupling-element secondary body portion;

a second coupling element having a second-coupling-element longitudinalaxis and shaped so as to define:

-   -   a second-coupling-element main body portion shaped so as to        define second-coupling-element-main-body passage;    -   a second-coupling-element secondary body portion coaxial with        the second-coupling-element main body portion, the        second-coupling-element secondary body portion shaped so as to        define a second-coupling-element-secondary-body-portion passage        coaxial with the second-coupling-element-main-body passage; and    -   a second-coupling-element connecting element connecting the        second-coupling-element secondary body portion to the        second-coupling-element main body portion,

wherein:

-   -   the second coupling element is shaped so as to define a        second-coupling-element space between the        second-coupling-element main body portion and the        second-coupling-element secondary body portion, and    -   the first and second coupling elements are couplable together by        fitting the first-coupling-element secondary body portion within        the second-coupling-element space of the second coupling        element, and by fitting the second-coupling-element secondary        body portion within the first-coupling-element space of the        first coupling element in a manner in which the        first-coupling-element-main-body passage, the        first-coupling-element-secondary-body-portion passage, the        second-coupling-element-main-body passage, and the        second-coupling-element-secondary-body-portion passage are        aligned; and

an elongate longitudinal element:

-   -   disposable within the first-coupling-element-main-body passage,        the first-coupling-element-secondary-body-portion passage, the        second-coupling-element-main-body passage, and the        second-coupling-element-secondary-body-portion passage to        maintain coupling of the first coupling element to the second        coupling element, and    -   removable from the first-coupling-element-main-body passage, the        first-coupling-element-secondary-body-portion passage, the        second-coupling-element-main-body passage, and the        second-coupling-element-secondary-body-portion passage to        facilitate decoupling of the first and second coupling elements.

In some applications of the present invention, the elongate longitudinalelement includes a rod.

In some applications of the present invention, thefirst-coupling-element main body portion is shaped so as to define acylinder.

In some applications of the present invention, thesecond-coupling-element main body portion is shaped so as to define acylinder.

In some applications of the present invention, the first couplingelement is coupled to a tissue anchor and the second coupling element iscoupled to a tissue-anchor-delivering tool.

In some applications of the present invention, the tissue anchorincludes a helical tissue anchor, and the tissue-anchor-delivering toolincludes a torque-delivering tool configured to corkscrew the helicaltissue anchor into tissue of a patient.

In some applications of the present invention, the torque-deliveringtool is coupled to the second coupling element.

In some applications of the present invention, the apparatus includes aconnecting element shaped to define an annular loop surrounding aproximal portion of the first coupling element, in a manner whichenables rotation of the anchor and the first coupling element about thefirst-coupling-element longitudinal axis, when surrounded by the annularloop.

In some applications of the present invention, the apparatus includes aflexible, longitudinal band coupled to the connecting element, and thetissue anchor and the first coupling element are configured to rotatewith respect to the flexible, longitudinal band.

There is further provided, in accordance with some applications of thepresent invention, a method, including:

providing a first coupling element having a first-coupling-elementlongitudinal axis and shaped so as to define:

-   -   a first-coupling-element main body portion shaped so as to        define first-coupling-element-main-body passage;    -   a first-coupling-element secondary body portion coaxial with the        main body portion, the first-coupling element secondary body        portion shaped so as to define a        first-coupling-element-secondary-body-portion passage coaxial        with the first-coupling-element-main-body passage; and

a connecting element connecting the secondary body portion to the mainbody portion,

wherein the first coupling element is shaped so as to define afirst-coupling-element space between the main body portion and thesecondary body portion;

providing a second coupling element having a second-coupling-elementlongitudinal axis and shaped so as to define:

-   -   a second-coupling-element main body portion shaped so as to        define second-coupling-element-main-body passage;    -   a second-coupling-element secondary body portion coaxial with        the main body portion, the second-coupling element secondary        body portion shaped so as to define a        second-coupling-element-secondary-body-portion passage coaxial        with the second-coupling-element-main-body passage; and    -   a connecting element connecting the secondary body portion to        the main body portion,

wherein the second coupling element is shaped so as to define asecond-coupling-element space between the main body portion and thesecondary body portion;

coupling together the first and second coupling elements are couplabletogether by fitting the first-coupling-element secondary body portionwithin the second-coupling-element space of the second coupling element,and by fitting the second-coupling-element secondary body portion withinthe first-coupling-element space of the first coupling element in amanner in which the first-coupling-element-main-body passage, thefirst-coupling-element-secondary-body-portion passage, thesecond-coupling-element-main-body passage, and thesecond-coupling-element-secondary-body-portion passage are aligned;

maintaining the coupling by inserting an elongate longitudinal elementwithin the first-coupling-element-main-body passage, thefirst-coupling-element-secondary-body-portion passage, thesecond-coupling-element-main-body passage, and thesecond-coupling-element-secondary-body-portion passage to maintaincoupling of the first coupling element to the second coupling element;and

facilitating decoupling of the first and second coupling elements byremoving the elongate longitudinal element.

In some applications of the present invention, the elongate longitudinalelement includes a rod.

In some applications of the present invention, the method includesproviding a tissue anchor coupled to the first coupling element, andproviding a tissue-anchor-delivery tool coupled to the second element.

In some applications of the present invention, the tissue anchorincludes a helical tissue anchor, and the tissue-anchor-delivery toolincludes a torque-delivering tool configured to deliver torque to thetissue anchor to corkscrew the helical tissue anchor into tissue of apatient.

In some applications of the present invention, corkscrewing the helicaltissue anchor includes rotating the first coupling element and theanchor about the first-coupling-element longitudinal axis, and rotatingincludes rotating the first coupling element and the anchor with respectto a connecting element coupled to an annular loop surrounding aproximal portion of the first coupling element.

In some applications of the present invention, rotating includesrotating the first coupling element and the anchor with respect to aflexible, longitudinal band coupled to the connecting element.

There is also provided, in accordance with some applications of thepresent invention, apparatus including:

a first tissue-engaging element;

at least one flexible longitudinal member coupled at a first end portionthereof to at least a portion of the first tissue-engaging element;

a second tissue-engaging element including a stent, the secondtissue-engaging element being coupled to the first tissue-engagingelement via the at least one flexible longitudinal member; and

a flexible-longitudinal-member-adjustment mechanism coupled to the atleast one flexible longitudinal member, theflexible-longitudinal-member-adjustment mechanism being configured toadjust a length of the selected flexible longitudinal member to draw thefirst and second tissue-engaging elements toward each other.

In some applications of the present invention, theflexible-longitudinal-member-adjustment mechanism includes a spoolconfigured to adjust a length of the at least one flexible longitudinalmember by winding a portion of the at least one flexible longitudinalmember around the spool.

The present invention will be more fully understood from the followingdetailed description of applications thereof, taken together with thedrawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-D are schematic illustrations of apparatus for reducingregurgitation of a heart valve which comprises a stent, a tissue anchor,and a tensioning element that couples the stent and the tissue anchor,in accordance with some applications of the present invention;

FIGS. 2A-B are schematic illustrations of apparatus for reducingregurgitation of the heart valve which comprises first and secondstents, first and second tissue anchor, and first and second tensioningelements, in accordance with some applications of the present invention;

FIGS. 3A-C are schematic illustrations of apparatus for reducingregurgitation of the heart valve which comprises a single stent, firstand second tissue anchor, and first and second tensioning elements, inaccordance with some applications of the present invention;

FIGS. 4A-C are schematic illustrations of apparatus for reducingregurgitation of a tricuspid valve which comprises first and secondstents and first and a tensioning element that couples the first andsecond stents, in accordance with some applications of the presentinvention;

FIGS. 5A-B are schematic illustrations of apparatus for reducingregurgitation of the heart valve which comprises two or three tissueanchors and a tensioning element that couples the tissue anchors, inaccordance with some applications of the present invention;

FIG. 6 is a schematic illustration of apparatus for reducingregurgitation of the heart valve which comprises a first anchoringsystem in the inferior vena cava, a first tissue anchor implanted at thevalve, and a second tissue anchor implanted in the papillary muscle;

FIGS. 7A-D are schematic illustrations of a delivery system for ahelical tissue anchor, in accordance with some applications of thepresent invention;

FIGS. 8 and 9 are schematic illustrations of a system for repairing atricuspid valve, using a superior vena cava approach and an inferiorvena cava approach, respectively, in accordance with respectiveapplications of the present invention;

FIGS. 10A-D are schematic illustrations of tissue anchors, in accordancewith respective applications of the present invention;

FIGS. 11A-C are schematic illustrations of another delivery system for ahelical tissue anchor, in accordance with some applications of thepresent invention;

FIGS. 12A-C are schematic illustrations of the release of the tissueanchor from the delivery system of FIGS. 11A-C, in accordance with someapplications of the present invention;

FIGS. 13A-C are schematic illustrations of a stent coupled to a helicalanchor, in accordance with some applications of the present invention;

FIGS. 14A-C are schematic illustrations of another stent coupled to ahelical anchor, in accordance with some applications of the presentinvention;

FIGS. 15A-B are schematic illustrations of yet another stent coupled toa helical anchor, in accordance with some applications of the presentinvention;

FIGS. 16A-B are schematic illustrations of a first and a second stentconfigured to be disposed concentrically, in accordance with someapplications of the present invention;

FIG. 17 is a schematic illustration of apparatus for reducingregurgitation of a heart valve which comprises a stent, a tissue anchor,and a tensioning element that couples the stent and the tissue anchor,in accordance with some applications of the present invention;

FIGS. 18A-B are schematic illustrations of an alternative portion of thedelivery system of FIGS. 11A-C, in accordance with some applications ofthe present invention;

FIG. 19 is a schematic illustration of an endoluminal implant coupled toa helical anchor, in accordance with some applications of the presentinvention;

FIGS. 20-26 are schematic illustrations of apparatus for reducingregurgitation of a heart valve which comprises a stent, a tissue anchor,and first and second flexible longitudinal members that couple the stentand the tissue anchor using respective coupling elements, in accordancewith some applications of the present invention;

FIG. 27 is a schematic illustration of aflexible-longitudinal-member-adjustment mechanism for adjusting a lengthof at least one of the first and second flexible longitudinal members ofFIGS. 20-26, in accordance with some applications of the presentinvention;

FIG. 28 is a schematic illustration of respective coupling elements ofthe first and second flexible longitudinal members of FIGS. 20-26, inaccordance with another application of the present invention;

FIGS. 29 and 30A-D are schematic illustrations of respective couplingelements of the first and second flexible longitudinal members of FIGS.20-26, in accordance with yet another application of the presentinvention;

FIG. 31 is a schematic illustration of respective coupling elements ofthe first and second flexible longitudinal members of FIGS. 20-26, inaccordance with still yet another application of the present invention;

FIG. 32 is a schematic illustration of a flexible longitudinal guidemember reversibly coupled to one of the coupling elements of FIGS.20-31, in accordance with some applications of the present invention;

FIGS. 33A-B are schematic illustrations of a firstflexible-longitudinal-member-coupling element coupled to a secondflexible-longitudinal-member-coupling element, in accordance with anapplication of the present invention;

FIGS. 34A-E are schematic illustrations of a method for deploying asystem for repairing the tricuspid valve, in accordance with anapplication of the present invention;

FIGS. 35A-C are schematic illustrations of another configuration of thefirst flexible-longitudinal-member-coupling element of FIGS. 33A-B,coupled to the second flexible-longitudinal-member-coupling element ofFIGS. 33A-B, in accordance with an application of the present invention;

FIGS. 36A-B are schematic illustrations of a link of the firstflexible-longitudinal-member-coupling element of FIGS. 35A-C, inaccordance with an application of the present invention;

FIGS. 37A-B and 38A-C are schematic illustrations of two respectiveconfigurations of another first flexible-longitudinal-member-couplingelement, coupled to the second flexible-longitudinal-member-couplingelement of FIGS. 33A-B, in accordance with respective applications ofthe present invention;

FIGS. 39A-B are schematic illustrations of another firstflexible-longitudinal-member-coupling element and another secondflexible-longitudinal-member-coupling element coupled thereto, inaccordance with an application of the present invention; and

FIGS. 40A-E are schematic illustrations of a method for deploying asystem for repairing the tricuspid valve, in accordance with anapplication of the present invention.

DETAILED DESCRIPTION OF APPLICATIONS

Reference is now made to FIGS. 1A-D, which are schematic illustrationsof a system 20 comprising a first tissue-engaging element 60 a and asecond tissue-engaging element 60 b for repairing a tricuspid valve 4 ofa heart 2 of a patient, in accordance with some applications of thepresent invention. First tissue-engaging element 60 a comprises a tissueanchor 40 which is designated for implantation at least in part incardiac tissue at a first implantation site 30. It is to be noted thattissue anchor 40 comprises a helical tissue anchor by way ofillustration and not limitation and that tissue anchor 40 may compriseany tissue anchor for puncturing or clamping cardiac tissue, including,but not limited to, the tissue anchors described hereinbelow withreference to FIGS. 7A-D, 10A-D 11A-C, 12A-C, 13A-C, and 14A-C. Secondtissue-engaging element 60 b comprises a percutaneous implant, forexample, an endoluminal implant, e.g., stent 50, which is designated forimplantation in a portion of a blood vessel, e.g., a superior vena cava10 (not shown) or an inferior vena cava 8 (such as shown in FIGS. 1A-D),at a second implantation site 52. First and second tissue-engagingelements 60 a and 60 b are coupled together by a flexible longitudinalmember 42. Typically, a distance between first and second implantationsites 30 and 52 is adjusted by pulling to apply tension to or relaxinglongitudinal member 42 and/or by applying tension to at least one offirst and second tissue-engaging elements 60 a and 60 b. Responsively, adistance between the leaflets of tricuspid valve 4 is adjusted to reduceand eliminate regurgitation through and thereby repair tricuspid valve4. For some applications, longitudinal member 42 is pulled or relaxed bymanipulating second tissue-engaging element 60 b, as is describedhereinbelow.

Typically, longitudinal member 42 comprises a flexible biocompatibletextile e.g. polyester, nylon, PTFE, ePTFE, PEEK, PEBAX™, and/orsuperelastic material, e.g., nitinol. Typically, longitudinal member 42comprises a plurality of fibers which are aligned, e.g., woven orintertwined, to form a fabric band, as will be described hereinbelowwith reference to FIGS. 11A-C, 13C, and 14C. In some applications of thepresent invention, longitudinal member 42 comprises a braided polyestersuture (e.g., DACRON™). In other applications of the present invention,longitudinal member 42 is coated with polytetrafluoroethylene (PTFE). Insome applications of the present invention, longitudinal member 42comprises a plurality of wires that are intertwined to form a ropestructure. For some applications, at least a part of longitudinal member42 comprises a tension spring and/or a plurality of coils.

For some applications, first and second tissue-engaging elements 60 aand 60 b and longitudinal member 42 are fabricated from the samematerial, e.g., nitinol, from a single piece. That is, first and secondtissue-engaging elements 60 a and 60 b and longitudinal member 42 definea single continuous implant unit. For some applications, at least secondtissue-engaging element 60 b and longitudinal member 42 are fabricatedfrom a single piece.

For some applications, second tissue-engaging element 60 b comprises astent 50 which is advanced toward and expandable in a portion ofinferior vena cava 8 (such as shown in FIGS. 1A-D) or superior vena cava10 (not shown), i.e., a blood vessel that is in direct contact with aright atrium 6 of heart 2 of the patient. Second tissue-engaging element60 b is implanted at second implantation site 52. As shown, firstimplantation site comprises a portion of an annulus of tricuspid valve4, specifically the anteroposterior commissure by way of illustrationand not limitation. For some applications, implantation site 30typically comprises a portion of the annulus of tricuspid valve 4 thatis between (1) the middle of the junction between the annulus andanterior leaflet 14, and (2) the middle of the junction between theannulus and posterior leaflet 16, e.g., between the middle of thejunction between the annulus and anterior leaflet 14 and the commissurebetween the anterior and posterior leaflets. That is, anchor 40 iscoupled to, e.g., screwed into, the fibrous tissue of the tricuspidannulus close to the commissure in between anterior leaflet 14 andposterior leaflet 16. Implantation site 30 is typically close to themural side of tricuspid valve 4. For such applications, the drawingtogether of first and second implantation sites 30 and 52 cinchestricuspid valve 4 and may create a bicuspidization of tricuspid valve 4,and thereby achieve stronger coaptation between anterior leaflet 14 andseptal leaflet 12. During the bicuspidization, posterior leaflet 16 maybe offset outside the plane of tricuspid valve 4.

For some applications, first implantation site 30 may include a portionof tissue of a wall defining right atrium 6 of heart 2, typically in avicinity of the annulus of tricuspid valve 4, e.g., theanterior-posterior commissure, as shown. For other applications, firstimplantation site 30 may include a portion of a wall of a rightventricle of heart 2, a ventricular portion of the annulus of tricuspidvalve 4, or a portion of a papillary muscle of the right ventricle ofheart 2, as is shown hereinbelow in FIG. 6. First implantation site 30is typically a distance away from, e.g., generally opposite, secondimplantation site 52 so that, following adjusting of longitudinal member42, first and second implantation sites 30 and 52 are drawn together,and thereby at least first and second leaflets, e.g., all threeleaflets, of tricuspid valve 4 are drawn toward each other. Forapplications in which first implantation site 30 includes a portion oftissue of the annulus, the adjusting of the distance betweenimplantation sites 30 and 52 alters the geometry of (i.e., changes theconfiguration of) the annulus of tricuspid valve 4 and thereby drawstogether the leaflets of tricuspid valve 4. For applications in whichfirst implantation site 30 includes tissue of a portion of a wall thatdefines atrium 6, the adjusting of the distance between implantationsites 30 and 52 alters the geometry of (i.e., changes the configurationof) the wall of atrium 6 and thereby draws together the leaflets oftricuspid valve 4.

FIG. 1A shows the advancement of a catheter 22 toward atrium 6 of thepatient until a distal end 23 of the catheter is disposed within atrium6, as shown. The procedure is typically performed with the aid ofimaging, such as fluoroscopy, transesophageal echo, and/orechocardiography. For some applications, the procedure begins byadvancing a semi-rigid guidewire into right atrium 6 of the patient. Theguidewire provides a guide for the subsequent advancement of a catheter22 therealong and into the right atrium. For some applications, oncedistal end 23 of catheter 22 has entered right atrium 6, the guidewireis retracted from the patient's body. Catheter 22 typically comprises a14-20 F sheath, although the size may be selected as appropriate for agiven patient. Catheter 22 is advanced through vasculature into rightatrium 6 using a suitable point of origin typically determined for agiven patient. For example:

-   -   catheter 22 may be introduced into the femoral vein of the        patient, through inferior vena cava 8, and into right atrium 6;    -   catheter 22 may be introduced into the basilic vein, through the        subclavian vein through superior vena cava 10, and into right        atrium 6; or    -   catheter 22 may be introduced into the external jugular vein,        through the subclavian vein through superior vena cava 10, and        into right atrium 6.

As shown in FIG. 1A, catheter 22 is advanced through inferior vena cava8 of the patient and into right atrium 6 using a suitable point oforigin typically determined for a given patient. Alternatively, catheter22 is advanced through superior vena cava 10 of the patient and intoright atrium 6 using a suitable point of origin typically determined fora given patient.

Once distal end 23 of catheter 22 is disposed within atrium 6, ananchor-deployment tube 24 is extended from within catheter 22 beyonddistal end 23 thereof and toward first implantation site 30.Anchor-deployment tube 24 holds tissue anchor 40 and a distal portion oflongitudinal member 42. For some applications, tube 24 is steerable, asis known in the catheter art, while for other applications, a separatesteerable element may be coupled to anchor-deployment tube 24. Under theaid of imaging guidance, anchor-deployment tube 24 is advanced towardfirst implantation site 30 until a distal end thereof contacts cardiactissue of heart 2 at first implantation site 30. Anchor-deployment tube24 facilitates atraumatic advancement of first tissue-engaging element60 a toward first implantation site 30. For such applications in whichanchor-deployment tube 24 is used, stent 50 is compressed within aportion of tube 24.

An anchor-manipulating tool (not shown for clarity of illustration),which is slidably disposed within anchor-deployment tube 24, is sliddistally within tube 24 so as to push distally tissue anchor 40 of firsttissue-engaging element 60 a and expose tissue anchor 40 from withintube 24, as shown in FIG. 1B. For some applications of the presentinvention, the anchor-manipulating tool is reversibly coupled to anchor40 and facilitates implantation of anchor 40 in the cardiac tissue. Forapplications in which anchor 40 comprises a helical tissue anchor, asshown, the operating physician rotates the anchor-manipulating tool froma site outside the body of the patient in order to rotate anchor 40 andthereby screw at least a portion of anchor 40 in the cardiac tissue.

Alternatively, system 20 is provided independently of theanchor-manipulating tool, and anchor-deployment tube 24 facilitatesimplantation of anchor 40 in the cardiac tissue. For applications inwhich anchor 40 comprises a helical tissue anchor, as shown, theoperating physician rotates anchor-deployment tube 24 from a siteoutside the body of the patient in order to rotate anchor 40 and therebyscrew at least a portion of anchor 40 in the cardiac tissue.

It is to be noted that for some applications of the present invention,anchor 40 comprises a clip, jaws, or a clamp which grips and squeezes aportion of cardiac tissue and does not puncture the cardiac tissue.

Following the implantation of anchor 40 at first implantation site 30,anchor-deployment tube 24 is retracted within catheter 22 in order toexpose longitudinal member 42, as shown in FIG. 1C. Subsequently,longitudinal member 42 is pulled taut in order to repair tricuspid valve4, as described hereinbelow.

For some applications, distal end 23 of catheter 22 is fixed in placewith respect to longitudinal member 42. Fixing in place catheter 22stabilizes catheter 22 as longitudinal member 42 is pulled. This enablesdistal end 23 to remain in place and not slide distally towardimplantation site 30 during the adjusting of longitudinal member 42. Forsome applications of the present invention, a proximal portion ofcatheter 22 and/or a proximal handle portion coupled to catheter 22 isanchored or otherwise fixed in place at its access location, e.g., bytaping or plastering. Alternatively or additionally, a distal portion ofcatheter 22 comprises an inflatable element coupled to an inflationconduit which runs the length of catheter 22 from the distal portionthereof to a site outside the body of the patient. Prior to theadjusting of longitudinal member 42, the inflatable element is inflatedsuch that it contacts tissue of the vasculature through which catheter22 is advanced, and thereby catheter 22 is fixed in place. Typically,the inflatable element comprises an annular inflatable element, suchthat when inflated, the annular inflatable element functions as a sealto hold in place the distal portion of catheter 22.

(In this context, in the specification and in the claims, “proximal”means closer to the orifice through which the implant (i.e., theprosthetic valve and the valve support) is originally placed into thebody of the patient, along the path of delivery of the implant, and“distal” means further from this orifice along the path of delivery ofthe implant.)

Following the fixation of the mechanism that facilitates pulling oflongitudinal member 42, the physician then pulls longitudinal member 42and thereby draws together first and second implantation sites 30 and52.

For some applications, catheter 22 is reversibly coupled to a proximalportion of longitudinal member 42 by being directly coupled to theproximal portion of member 42 and/or catheter 22 is reversibly coupledto second tissue-engaging element 60 b. For example, catheter 22 may bereversibly coupled to stent 50 by the stent's application of a radialforce against the inner wall of catheter 22 because of the tendency ofstent 50 to expand radially. Following implantation of firsttissue-engaging element 60 a, catheter 22 (or an element disposedtherein) is then pulled proximally to apply tension to longitudinalmember 42, which, in such an application, functions as a tensioningelement. For some applications, catheter 22 pulls on secondtissue-engaging element 60 b in order to pull longitudinal member 42.For other applications, catheter 22 pulls directly on longitudinalmember 42. For yet other applications, a pulling mechanism pulls onlongitudinal member 42, as is described hereinbelow with reference toFIGS. 7A-D.

Pulling longitudinal member 42 pulls taut the portion of longitudinalmember 42 that is disposed between anchor 40 and distal end 23 ofcatheter 22. Additionally, longitudinal member 42 may be pulled orrelaxed in order to adjust the distance between first and secondimplantation sites 30 and 52. Responsively to the pulling oflongitudinal member 42, at least the anterior and septal leaflets oftricuspid valve 4 are drawn together because the geometry of the annulusand/or of the wall of atrium 6 is altered in accordance with the pullingof longitudinal member 42 and depending on the positioning of firsttissue-engaging element 60 a. For some applications, during the pullingof longitudinal member 42 by catheter 22, a level of regurgitation oftricuspid valve 4 is monitored and a parameter indicative of repair oftricuspid valve 4 is monitored. For example, leaflet anatomy during theopening and closing of tricuspid valve 4 is assessed using an imagingdevice such as intracardiac echocardiography, transthoracicechocardiography or transesophageal echocardiography. For someapplications, during the monitoring, measurements used to assess theefficiency of the procedure are evaluated pre-, during, andpost-procedure. For example, these measurements could include, but notexclusively, measuring the echocardiographic distance between theanteroposterior commissure and the rim at the junction of the inferiorvena cava and the right atrium, or measuring the echocardiographicregurgitant volume through tricuspid valve 4. Longitudinal member 42 ispulled until the regurgitation is reduced or ceases.

Once the physician determines that the regurgitation of tricuspid valve4 is reduced or ceases, and tricuspid valve 4 has been repaired, thephysician decouples catheter 22 from second tissue-engaging element 60 bdisposed therein and/or from longitudinal member 42, and then retractscatheter 22 in order to expose second tissue-engaging element 60 b,i.e., stent 50. During the advancement of catheter 22 toward atrium 6,stent 50 is disposed within a distal portion of catheter 22 in acompressed state. Following initial retracting of catheter 22, stent 50is exposed and is allowed to expand and contact a wall of inferior venacava 8. Responsively to the expanding, stent 50 is implanted in secondimplantation site 52 and maintains the tension of longitudinal member 42on anchor 40 and thereby on the portion of cardiac tissue to whichanchor 40 is coupled.

Reference is again made to FIGS. 1A-D. For some applications, followingthe implantation of first and second tissue-engaging elements 60 a and60 b, a distance between first and second tissue-engaging elements 60 aand 60 b is adjusted by an adjustable mechanism, as describedhereinbelow with reference to FIGS. 5A-B. In such applications, a lengthof longitudinal member 42 between first and second tissue-engagingelements 60 a and 60 b may be adjusted by an adjusting mechanism 150, asshown in FIGS. 5A-B. Adjusting mechanism 150 typically comprises amechanical element which shortens a distance of longitudinal member 42between first and second tissue-engaging elements 60 a and 60 b. Forsome applications, adjustable mechanism 150 may be permanently coupledto longitudinal member 42 (not shown) and comprises an adjustingelement, e.g., a spool for looping portions of longitudinal member 42therearound, a crimping bead for crimping and shortening a portion oflongitudinal member 42, a ratchet element, or a deforming element whichdeforms a portion of longitudinal member 42 in order to shorten itslength between first and second tissue-engaging elements 60 a and 60 b.A level of regurgitation of tricuspid valve 4 may be monitored duringthe adjusting of the distance between first and second tissue-engagingelements 60 a and 60 b by adjusting mechanism 150.

For some applications, such as shown in FIG. 1D, stent 50 comprises aplurality of interconnected superelastic metallic struts, arranged so asto allow crimping the stent into a relatively small diameter (typicallyless than 8 mm) catheter, while allowing deployment to a much largerdiameter (typically more than 20 mm) in the vena cava, while stillmaintaining radial force against the vena cava tissue, in order toanchor stent 50 to the wall of the vena cava by friction.

For some applications, such as those described with reference to FIGS.1A-D, longitudinal member 42 has a length of at least 10 mm, no morethan 40 mm, and/or between 10 and 40 mm.

The configuration of stent 50 that is shown in FIG. 1D deployed ininferior vena cava 8 may instead be deployed in superior vena cava 10(deployment not shown).

Reference is now made to FIGS. 7A-D, which are schematic illustrationsof a delivery tool system 200 for implanting anchor 40, in accordancewith some applications of the present invention. Delivery tool system200 may be used, for example, to rotate and implant an anchor incombination with the applications described herein with reference toFIGS. 1A-D, 2A-B, 3A-C, 5A-B, 6, 8, 9, 13A-C, 14A-C, 15A-B, 16A-B, and17. Although longitudinal member 42 is shown in FIGS. 7A-D as beingfixed to stent 50, this is not necessarily the case, and tool system 200thus may also be used in combination with the applications that do notutilize stent 50, such as those described herein with reference to FIGS.3C and 5A-B.

Reference is now made to FIGS. 1A-D and 7A-D. It is to be noted thatanchor 40 may be implanted using delivery tool system 200. FIG. 7A showsan exploded view of the components of delivery tool system 200 and itsspatial orientation relative to stent 50, longitudinal member 42, andanchor 40. In such an application, a distal end of longitudinal member42 comprises an annular loop 216, through which a portion of anchor 40is coupled to the distal end of longitudinal member 42. For some suchapplications, stent 50, longitudinal member 42, and anchor 40 are notfabricated from the same piece, as described hereinabove; rather, onlystent 50, longitudinal member 42, and annular loop 216 are typicallyfabricated from a single piece, and anchor 40 is coupled to longitudinalmember 42 via annular loop 216. Alternatively, as mentioned above,longitudinal member 42 is not coupled to stent 50, such as forapplications in which stent 50 is not provided.

System 200 typically comprises an adapter 218, which, for someapplications, is shaped so as to define an annular proximal portion anda distal cylindrical portion having a distal end 220. During themanufacture of system 200, distal end 220 of the cylindrical portion ofadapter 218 is slid through annular loop 218 at the distal end oflongitudinal member 42, thereby coupling adapter 218 to the distal endof longitudinal member 42. Distal end 220 of adapter 218 is then weldedor otherwise fixedly coupled to a proximal portion of an inner lumen ofanchor 40, as shown in FIG. 7B. This coupling arrangement of anchor 40to annular loop 216 and adapter 218 enables anchor 40 to rotate about acentral longitudinal axis of delivery system 200, freely within annularloop 216. That is, delivery tool system 200 rotates anchor 40 withoutrotating longitudinal member 42 and stent 50 (if provided), as describedhereinbelow.

Delivery tool system 200 comprises a delivery tool overtube 202 having adistal end thereof. For application in which stent 50 is provided,delivery tool overtube 202 is housed within catheter 22 such that adistal portion thereof passes in part through the lumen of stent 50 anda distal end 204 thereof extends toward tissue anchor 40. Duringdelivery of tissue anchor 40 and stent 50 toward their respectiveimplantation sites, deliver tool system 200 assumes the configurationshown in FIG. 7B. It is to be noted, however, that stent 50 iscompressed around the portion of overtube 202 that extends through thelumen of stent 50 (not shown for clarity of illustration), and thatcatheter 22 (not shown for clarity of illustration) surrounds system 200(and thereby compresses stent 50).

Reference is again made to FIG. 7A. Overtube 202 houses atorque-delivering and an anchor-pulling tube 208 and facilitatesslidable coupling of tube 208 to overtube 202. A distal end oftorque-delivering and anchor-pulling tube 208 is coupled to amanipulator 206 which is shaped so as to define a coupling 210 whichcouples manipulator 206 to adapter 218, and thereby, to anchor 40. Inorder to rotate anchor 40, torque-delivering and anchor-pulling tube 208is rotated. As torque-delivering and anchor-pulling tube 208 is rotated,manipulator 206 is rotated in order to screw anchor 40 into the cardiactissue of the patient. As adapter 218 rotates, the cylindrical portionthereof rotates freely within annular loop 216. This couplingarrangement of adapter 218 (and thereby anchor 40) to loop 216 (andthereby longitudinal member 42) enables the physician to rotate andimplant anchor 40 without rotating longitudinal member 42 and stent 50(if provided).

Following rotation of anchor 40, torque-delivering and anchor-pullingtube 208 is pulled by the physician in order to pull on anchor 40 andthereby on the portion of cardiac tissue to which anchor 40 is implantedat first implantation site 30. Tube 208 is typically coupled at aproximal end thereof to a mechanical element, e.g., a knob, at thehandle portion outside the body of the patient. The physician pulls ontube 208 by actuating the mechanical element that is coupled to theproximal end of tube 208. This pulling of tube 208, and thereby ofanchor 40 and of cardiac tissue at first implantation site 30, drawsfirst implantation site toward second implantation site 52 and therebydraws at least anterior leaflet 14 toward septal leaflet 12 in order toachieve coaptation of the leaflets and reduce regurgitation throughvalve 4.

For some applications in which stent 50 is provided, following thepulling of anchor 40, stent 50 is positioned at second implantation site52. Catheter 22 is then retracted slightly along tube 202 so as to pulltaut longitudinal member 42 and to ensure that tension is maintained atfirst implantation site 30 and along longitudinal member 42. Stent 50 isthen deployed when the physician holds torque-delivering andanchor-pulling tool 208 and then retracts proximally either (1) catheter22 or (2) a sheath (i.e., that is disposed within catheter 22 andsurrounds stent 50), around stent 50 so as to deploy stent 50 fromwithin either (1) catheter 22 or (2) the sheath disposed within catheter22.

It is to be noted that stent 50 is retrievable following at leastpartial deployment thereof, e.g., following deployment of up to ½ or upto ⅓ of stent 50. In such an application, following the initialretraction proximally of catheter 22 from around stent 50 in order todeploy at least a distal portion of stent 50, catheter 22 is advanceabledistally so as to compress and retrieve the at least partially-deployedstent back into the distal end portion of catheter 22. Alternatively,catheter 22 houses a sheath which compresses stent 50 during delivery ofstent to second implantation site 52. During the initial retracting ofcatheter 22 proximally, the sheath surrounding stent 50 is alsoretracted in conjunction with the retracting of catheter 22. Followingthe at least partial deployment of stent 50 in order to deploy at leasta distal portion of stent 50, the sheath is advanceable distally (whilecatheter 22 remains in place) so as to compress and retrieve the atleast partially-deployed stent back into the distal end portion of thesheath. The sheath is then retracted into catheter 22. For suchapplications of the present invention in which stent 50 is retrievablefollowing at least partial deployment thereof, anchor 40 can then beunscrewed from first implantation site 30 and the entire implant systemmay be extracted from the body, or repositioned in the heart, dependingon the need of a given patient.

For applications in which stent 50 is retrievable, in order to retrievestent 50 (i.e., prior to the decoupling of manipulator 206 from adapter218 and thereby from anchor 40), the physician holds torque-deliveringand anchor-pulling tool 208 and then advances distally either (1)catheter 22 or (2) the sheath disposed within catheter 22, around stent50 so as to compress stent 50 within either (1) catheter 22 or (2) thesheath disposed within catheter 22. Torque-delivering and anchor-pullingtool 208 may then be rotated in order to unscrew anchor 40 from thetissue, and the entire system may be extracted from the body, orrepositioned in the heart, depending on the need of a given patient.

Reference is again made to FIGS. 7A-D. FIGS. 7C-D show the decouplingand release of torque-delivering and anchor-pulling tube 208 andmanipulator 206 from adapter 218 and anchor 40. This release occurstypically following the deployment of stent 50 (if provided), asdescribed hereinabove. As shown in FIG. 7A, system 200 comprises areleasable adapter holder 212 which is shaped so as to define arms 214which have a tendency to expand radially. Holder 212 surroundsmanipulator 206, as shown in FIG. 7C. During the delivery of anchor 40toward implantation site 30 and the subsequent rotation of anchor 40 toscrew anchor 40 into tissue at site 30, a distal end 204 of overtube 202is disposed adjacently to loop 216 such that a distal end portion ofovertube 202 surrounds and compresses arms 214 of holder 212 (as shownin FIG. 7B). Following the pulling of anchor 40 by torque-delivering andanchor-pulling tube 208, overtube 202 is retracted slightly in order toexpose arms 214 of holder 212. Responsively, arms 214 expand radially(FIG. 7C) and release adapter 218 (and thereby anchor 40) from holder212.

As shown in FIG. 7D, overtube 202 is held in place while the physicianretracts tube 208 so as to collapse and draw arms 214 into the distalend portion of overtube 202. Overtube 202 is then slid proximally withincatheter 22 leaving behind anchor 40, adapter 218 coupled to anchor 40,loop 216, longitudinal member 42, and stent 50 (if provided). Catheter22, that houses overtube 202 and the components disposed therein, isextracted from the body of the patient.

For some applications, such as those described hereinabove withreference to FIGS. 7A-D, longitudinal member 42 has a length of at least10 mm, no more than 40 mm, and/or between 10 and 40 mm.

Reference is again made to FIGS. 1A-D. It is to be noted thattissue-engaging elements 60 a and 60 b may be implanted at theirrespective implantation sites 30 and 50, as described hereinabove, byadvancing catheter 22 and tissue-engaging elements 60 a and 60 b throughsuperior vena cava 10, mutatis mutandis.

FIGS. 2A-B show a system 100 for repairing tricuspid valve 4 comprisingfirst and second stents 50 a and 50 b, first and second longitudinalmembers 42 a and 42 b, and first and second tissue anchors 40 a and 40b. First tissue anchor 40 a defines first tissue-engaging element 60 a.First stent 50 a defines second tissue-engaging element 60 b. Secondtissue anchor 40 b defines a third tissue-engaging element 60 c. Secondstent 50 b defines a fourth tissue-engaging element 60 d. For someapplications of the present invention, following the implantation offirst tissue-engaging element 60 a and second tissue-engaging element 60b, such as described hereinabove with reference to FIGS. 1A-D, third andfourth tissue-engaging elements 60 c and 60 d are then implanted. Asdescribed hereinabove, first implantation site 30, as shown, comprises aportion of tissue that is in a vicinity of the commissure betweenanterior leaflet 14 and posterior leaflet 16. First implantation site 30may comprise a portion of tissue that is between (1) the middle of thejunction between the annulus and anterior leaflet 14, and (2) the middleof the junction between the annulus and posterior leaflet 16.

Following the implantation of first and second tissue-engaging elements60 a and 60 b, catheter 22 is retracted from the body of the patient.Outside the body of the patient, catheter 22 is reloaded with third andfourth tissue-engaging elements 60 c and 60 d. Catheter 22 is thenreintroduced within the body of the patient and is advanced toward rightatrium 6, as shown in FIG. 2A, such that distal end 23 thereof passesthrough first stent 50 a and toward atrium 6. It is to be noted that aproximal end portion of longitudinal member 42 a is coupled to secondtissue-engaging element 60 b and is not disposed within catheter 22.

Subsequently, a second tissue anchor 40 b (i.e., an anchor that issimilar to tissue anchor 40 a, as described hereinabove) is implanted ata second portion of cardiac tissue at a third implantation site 32.Third implantation site 32 includes a portion of cardiac tissue in thevicinity of tricuspid valve 4 (e.g., a second portion of tissue of theannulus of tricuspid valve 4, as shown). Third implantation site 32, asshown, comprises a portion of tissue that is between (1) the middle ofthe junction between the annulus and anterior leaflet 14, and (2) themiddle of the junction between the annulus and posterior leaflet 16. Forsome applications, third implantation site 32 may comprise a secondportion of the wall that defines right atrium 6. For other applications,third implantation site 32 may comprise a portion of cardiac tissue inthe right ventricle, e.g., a portion of the wall that defines the rightventricle, a ventricular portion of the annulus of tricuspid valve 4, ora portion of a papillary muscle of the right ventricle.

Following implantation of third tissue-engaging element 60 c, catheter22 is retracted and tension is applied to third tissue-engaging element60 c in a manner as described hereinabove with reference to FIGS. 1C-Dwith regard to the application of tension to implantation site 30.Additionally, tension is applied to a second longitudinal member 42 bwhich couples third and fourth tissue-engaging elements 60 c and 60 d,e.g., in a manner as described hereinabove with regard to the pulling offirst longitudinal member 42 a, with reference to FIG. 1C. As describedherein, a level of regurgitation of tricuspid valve 4 may be monitoredduring the pulling tissue of third implantation site 32 toward secondimplantation site 52 and of second longitudinal member 42 b.

Additionally, responsively to the pulling of tissue at first and thirdimplantation sites 30 and 32 toward second implantation site 52,anterior leaflet 14 is drawn toward septal leaflet 12, andbicuspidization is achieved. Also, responsively to the pulling, aportion of tissue that is between first and third implantation sites 30and 32 is cinched. Further, responsively to the pulling, posteriorleaflet 16 is reduced and moved out of a plane of tricuspid valve 4during the bicuspidization.

Reference is now made to FIG. 2B. Once the physician determines that theregurgitation of tricuspid valve 4 is reduced or ceases, and tricuspidvalve 4 has been repaired, catheter 22 is decoupled from fourthtissue-engaging element 60 d and/or from second longitudinal member 42b, and the physician retracts catheter 22 in order to expose fourthtissue-engaging element 60 d, i.e., second stent 50 b, as shown. Duringthe advancement of catheter 22 toward atrium 6, second stent 50 b isdisposed within a distal portion of catheter 22 in a compressed state.Following initial retracting of catheter 22, second stent 50 b isexposed and is allowed to expand within a lumen of first stent 50 a, asshown, in order to contact a wall of inferior vena cava 8. Responsivelyto the expanding, second stent 50 b is implanted in second implantationsite 52 and maintains the tension of second longitudinal member 42 b onsecond tissue anchor 40 b and thereby on the portion of cardiac tissueto which anchor 40 b is coupled.

It is to be noted that second stent 50 b is implanted within the lumenof first stent 50 a by way of illustration and not limitation, and thatfor some applications of the present invention, first and second stents50 a and 50 b may be implanted coaxially at second implantation site 52.

It is to be noted that third and fourth tissue-engaging elements 60 cand 60 d and second longitudinal member 42 b are typically fabricatedfrom the same material, e.g., nitinol, from a single piece. That is,third and fourth tissue-engaging elements 60 c and 60 d and secondlongitudinal member 42 b typically define a single continuous implantunit.

Reference is now made to FIGS. 3A-C, which are schematic illustrationsof a system 110 for repairing tricuspid valve 4, which comprises first,second, and third tissue-engaging elements 60 a, 60 b, and 60 c, andfirst and second longitudinal members 42 a and 42 b, in accordance withsome applications of the present invention. System 110 is similar tosystem 100 described hereinabove with reference to FIGS. 2A-B, with theexception that system 110 does not comprise second stent 50 b; rather,as shown in FIGS. 3B-C, a proximal end portion 112 of secondlongitudinal member 42 b is shaped so as to define one or more engagingelements 114 (e.g., hooks or barbs, as shown). Following the implantingof third tissue-engaging element 60 c and the subsequent pulling ofsecond longitudinal member 42 b, catheter 22 facilitates coupling ofengaging elements 114 with the struts of stent 50 (as shown in FIG. 3Cwhich is an enlarged image of stent 50 and the proximal portion ofsecond longitudinal member 42 b of FIG. 3B). The coupling of engagingelements 114 to stent 50 maintains the tension applied to longitudinalmember 42, and thereby maintains the tension on third tissue-engagingelement 60 c in order to maintain the remodeled state of tricuspid valve4.

It is to be noted that third tissue-engaging element 60 c, secondlongitudinal member 42 b, and engaging elements 114 and proximal endportion 112 of second longitudinal member 42 b are typically fabricatedfrom the same material, e.g., nitinol, from a single piece. That is,third tissue-engaging element 60 c, second longitudinal member 42 b, andengaging elements 114 and proximal end portion 112 of secondlongitudinal member 42 b typically define a single continuous implantunit.

Reference is now made to FIGS. 2A-B and 3A-C. For some applications,following the implantation the tissue-engaging elements at theirrespective implantation sites, as described hereinabove, a length ofeach one of first and second longitudinal members 42 a and 42 b isadjusted by an adjustable mechanism, as described hereinbelow withreference to FIGS. 5A-B. Adjusting mechanism 150 typically comprises amechanical element which shortens a length of each one of first andsecond longitudinal members 42 a and 42 b. For some applications, arespective adjustable mechanism 150 may be permanently coupled to eachone of first and second longitudinal members 42 a and 42 b (not shown);each mechanism 150 comprises an adjusting element, e.g., a spool forlooping respective portions of longitudinal members 42 a and 42 btherearound, a crimping bead for crimping and shortening respectiveportions of longitudinal members 42 a and 42 b, a ratchet element, or adeforming element which deforms respective portions of longitudinalmembers 42 a and 42 b. For other applications, the adjusting mechanismcomprises only an adjusting tool which may comprise an adjustingelement, e.g., a crimping bead for crimping and shortening respectiveportions of longitudinal members 42 a and 42 b, or a deforming elementwhich deforms respective portions of longitudinal members 42 a and 42 b.In either application, a level of regurgitation of tricuspid valve 4 maybe monitored during the adjusting of the respective lengths of first andsecond longitudinal members 42 a and 42 b.

FIGS. 4A-C show a system 120 for repairing tricuspid valve 4 comprisingfirst and second stents 130 and 132 implanted in superior vena cava 10and inferior vena cava, respectively, in accordance with someapplications of the present invention. A catheter 122 is advancedthrough vasculature of the patient such that a distal end 124 ofcatheter 122 toward superior vena cava 10, as shown in FIG. 4A. Catheter122 is advanced from a suitable access location, e.g., catheter 122 maybe introduced into the femoral vein of the patient, through inferiorvena cava 8, and toward superior vena cava 10. During the advancement ofcatheter 122 toward superior vena cava 10 and inferior vena cava 8,stents 130 and 132 are disposed within a distal portion of catheter 122in a compressed state.

In FIG. 4B, first stent 130 is deployed from within catheter 122 andexpands to contact tissue of a wall of superior vena cava 10. Thisportion of the wall of the superior vena cava defines first implantationsite 30 in such applications of the present invention. Additionally,first stent member 130 defines first tissue-engaging element 60 a insuch applications of the present invention. It is to be noted that theportion of superior vena cava 10 in which stent 130 is implanted definesa portion of tissue that is in the vicinity of tricuspid valve 4.

Catheter 122 is then retracted so as to pull and apply tension tolongitudinal member 42. Longitudinal member 42 is pulled directly bycatheter 122 and/or indirectly by pulling stent member 132 disposedwithin catheter 122. For some applications, during the pulling, a levelof regurgitation of tricuspid valve 4 may be monitored, becauseresponsively to the pulling, the geometry of the wall of atrium 6 isaltered and the leaflets of tricuspid valve 4 are drawn together so asto reduce and eliminate regurgitation of tricuspid valve 4.

Once the physician determines that the regurgitation of tricuspid valve4 is reduced or ceases, and tricuspid valve 4 has been repaired, thephysician decouples catheter 122 from second stent member 132 disposedtherein and/or from longitudinal member 42, and then retracts catheter122 in order to expose second tissue-engaging element 60 b, i.e., secondstent member 132, as shown. Following initial retracting of catheter122, second stent member 132 is exposed and is allowed to expand andcontact a wall of inferior vena cava 8, as shown in FIG. 4C.Responsively to the expanding, second stent member 132 is implanted insecond implantation site 52 and maintains the tension of longitudinalmember 42 on first stent member 130 and thereby maintains the alteredgeometry of the wall of atrium 6 and of the leaflets of tricuspid valve4.

Reference is again made to FIGS. 4A-C. For some applications, followingthe deploying of first and second tissue-engaging elements 60 a and 60 b(i.e., first and second stents 130 and 132, respectively), a distancebetween first and second tissue-engaging elements 60 a and 60 b isadjusted by an adjustable mechanism, as described hereinbelow withreference to FIGS. 5A-B. In such applications, a length of longitudinalmember 42 between first and second stents 130 and 132 may be adjusted byan adjusting mechanism 150, as shown in FIGS. 5A-B. Adjusting mechanism150 typically comprises a mechanical element which shortens a distanceof longitudinal member 42 between first and second stents 130 and 132.For some applications, adjustable mechanism 150 may be permanentlycoupled to longitudinal member 42 (not shown) and comprises an adjustingelement, e.g., a spool for looping portions of longitudinal member 42therearound, a crimping bead for crimping and shortening a portion oflongitudinal member 42, a ratchet element, or a deforming element whichdeforms a portion of longitudinal member 42 in order to shorten itslength between first and second stents 130 and 132. A level ofregurgitation and repair of tricuspid valve 4 may be monitored duringthe adjusting of the distance between first and second tissue-engagingelements 60 a and 60 b by adjusting mechanism 150.

It is to be noted that first and second stents 130 and 132 andlongitudinal member 42 are typically fabricated from the same material,e.g., nitinol, from a single piece. That is, first and second stents 130and 132 and longitudinal member 42 typically define a single continuousimplant unit.

Reference is yet again made to FIGS. 4A-C. It is to be noted that distalend 124 of catheter 122 may first be advanced toward inferior vena cava,and not first toward superior vena cava, as shown in FIG. 4A. In such anembodiment, catheter 122 may be introduced into the external jugularvein, through the subclavian vein, through superior vena cava 10, andtoward inferior vena cava 8. Alternatively, catheter 122 may beintroduced into the basilic vein, through the subclavian vein, throughsuperior vena cava and toward inferior vena cava 8. It is to be notedthat any suitable access location may be used to introduce catheter 122into the vasculature of the patient.

Reference is still made to FIGS. 4A-C. For some applications, one orboth of stents 130 and/or 132 comprise a plurality of interconnectedsuperelastic metallic struts, such as described hereinabove withreference to FIG. 1D.

Reference is now made to FIGS. 5A-B, which are schematic illustrationsof a system 140 for repairing tricuspid valve 4 comprising first andsecond tissue anchors 40 a and 40 b coupled together by longitudinalmember 42, in accordance with some applications of the presentinvention. In such applications, first tissue anchor 40 a defines firsttissue-engaging element 60 a, and second tissue anchor 40 b definessecond tissue-engaging element 60 b. Tissue anchors 40 a and 40 b maycomprise any suitable anchor for puncturing, squeezing, or otherwiseengaging cardiac tissue of the patient. As shown by way of illustrationand not limitation, tissue anchors 40 a and 40 b comprise helical tissueanchors which puncture and screw into the cardiac tissue. It is to benoted that first and second tissue-engaging elements 60 a and 60 b(i.e., first and second tissue anchors 40 a and 40 b) and longitudinalmember 42 are fabricated from the same material, e.g., nitinol, from asingle piece. That is, first and second tissue-engaging elements 60 aand 60 b and longitudinal member 42 define a single continuous implantunit.

A delivery catheter is advanced through vasculature of the patient, inmanner as described hereinabove with regard to catheter 22 withreference to FIG. 1A. The catheter is advanced toward first implantationsite 30 and facilitates implantation of first tissue anchor 40 a in thecardiac tissue. As shown, first implantation site 30 includes a firstportion of tissue of the annulus of tricuspid valve 4 at the mural sideof tricuspid valve 4, by way of illustration and not limitation. Forsome applications, first implantation site 30 may include a firstportion of the wall of atrium 6 of heart 2. As shown by way ofillustration and not limitation, first implantation site 30 includes aportion of tissue of the annulus at the commissure between anteriorleaflet 14 and posterior leaflet 16. It is to be noted that firstimplantation site 30 may be implanted at any suitable location along andin the vicinity of the annulus of tricuspid valve 4.

The delivery catheter is then advanced toward second implantation site52 and facilitates implantation of second tissue anchor 40 b in thecardiac tissue. For some applications, as the catheter is advancedtoward second implantation site, longitudinal member 42 is pulled todraw together the leaflets of tricuspid valve 4, while a level ofregurgitation of tricuspid valve 4 is monitored. As shown, secondimplantation site 52 includes a second portion of tissue of the annulusof tricuspid valve 4 at the septal side of tricuspid valve 4, by way ofillustration and not limitation. For some applications, secondimplantation site 52 may include a second portion of the wall of atrium6 of heart 2. As shown by way of illustration and not limitation, secondimplantation site 52 includes a portion of tissue of the annulusinferior of the middle of septal leaflet 12. It is to be noted thatfirst implantation site 30 may be implanted at any suitable locationalong and in the vicinity of the annulus of tricuspid valve 4, e.g., atthe commissure between posterior leaflet 16 and septal leaflet 12.

For such an application, by applying tension to longitudinal member 42,anterior leaflet 14 and septal leaflet 12 are drawn together, andbicuspidization of tricuspid valve 4 is achieved. For some applications,during the adjusting of mechanism 150, a retrievable stent may bedeployed in inferior vena cava 8 so as to stabilize system 140 duringthe adjusting of adjusting mechanism 150. It is to be further noted thattissue-engaging elements 60 a and 60 b and the delivery catheter may beadvanced toward atrium 6 through superior vena cava, mutatis mutandis.

For some applications of the present invention, system 140 comprises oneor more anchor-manipulating tools (not shown for clarity ofillustration), that is slidably disposed within the delivery catheter.The anchor-manipulating tool is slid distally with within the catheterso as to push distally tissue anchors 40 a and 40 b and expose tissueanchors 40 a and 40 b from within the catheter. For some applications ofthe present invention, the anchor-manipulating tool(s) is/are reversiblycouplable to anchors 40 a and 40 b, and facilitate(s) implantation ofanchors 40 a and 40 b in the cardiac tissue. For applications in whichanchors 40 a and 40 b comprises respective helical tissue anchor, asshown, the operating physician rotates the anchor-manipulating tool(s)from a site outside the body of the patient in order to rotate anchors40 a and 40 b, and thereby screw at least respective distal portions ofanchors 40 a and 40 b in the cardiac tissue.

Reference is again made to FIGS. 5A-B. It is to be noted that first andsecond implantation sites 30 and 52 include cardiac tissue that isupstream of tricuspid valve 4 by way of illustration and not limitation,and that either or both first and second implantation sites may includecardiac tissue that is downstream of tricuspid valve 4.

Typically, following implantation of first and second tissue anchors 40a and 40 b, a length of longitudinal member 42, that is disposed betweenfirst and second tissue anchors 40 a and 40 b, is adjusted by adjustingmechanism 150. Adjusting mechanism 150 typically comprises a mechanicalelement which shortens a distance of longitudinal member 42 betweenfirst and second tissue-engaging elements 60 a and 60 b. For someapplications, adjustable mechanism 150 may be permanently coupled tolongitudinal member 42 (as shown in FIG. 5B) and comprises an adjustingelement, e.g., a spool for looping portions of longitudinal member 42therearound, a crimping bead for crimping and shortening a portion oflongitudinal member 42, a ratchet element, or a deforming element whichdeforms a portion of longitudinal member 42 in order to shorten itslength between first and second tissue-engaging elements 60 a and 60 b.

For other applications, system 140 comprises only an adjusting tool(which functions as an adjusting mechanism) and not adjusting mechanism150. In such applications, the adjusting tool may comprise an adjustingelement, e.g., a crimping bead for crimping and shortening a portion oflongitudinal member 42, or a deforming element which deforms a portionof longitudinal member 42 in order to shorten its length between firstand second tissue-engaging elements 60 a and 60 b.

In either application, a level of regurgitation of tricuspid valve 4 maybe monitored during the adjusting of the distance between first andsecond tissue-engaging elements 60 a and 60 b by adjusting mechanism150.

Following the adjusting of the distance between first and secondimplantation sites 30 and 52, the adjusting tool and the deliverycatheter are decoupled from longitudinal member 42 and are extractedfrom the body of the patient.

Reference is now made to FIG. 5B, which is a schematic illustration ofanother configuration of system 140, in accordance with someapplications of the present invention. This configuration of system 140is generally similar to the configuration described above with referenceto FIG. 5A, except that the system comprises a third tissue-engagingelement 60 c (i.e., a third tissue anchor), in addition to first andsecond tissue-engaging elements 60 a and 60 b. Third tissue-engagingelement 60 c is implanted at third implantation site 32, such as usingthe techniques described hereinabove with reference to FIG. 5A. For someapplications, third implantation site 32 may include a third portion ofthe wall of atrium 6. By way of illustration and not limitation, thethree implantation sites may include portions of tissue of the annulusof the three leaflets of the valve, such as at the middle of theleaflets.

Tissue-engaging elements 60 a, 60 b, and 60 c are coupled tolongitudinal members 42 a, 42 b, and 42 c, respectively. Thelongitudinal members are coupled together by adjusting mechanism 150.For some applications, adjusting mechanism 150 comprises a spool forlooping portions of the longitudinal members therearound, and a ratchetelement which allows the spool to rotate in only one direction. Rotationof the spool loops the longitudinal member therearound, therebyshortening the effective lengths of the members and applying tensionthereto, to draw the leaflets toward one another, such as describedhereinabove with reference to FIG. 5A. As a result, a geometry of thewall of the right atrium may be altered.

Reference is now made to FIG. 6 which is a schematic illustration of asystem 700 for repairing tricuspid valve 4 comprising firsttissue-engaging element 60 a implanted at a portion of the annuls oftricuspid valve 4 and a third tissue-engaging element 60 c implanted ata portion of a papillary muscle 72 in the right ventricle of thepatient, in accordance with some applications of the present invention.It is to be noted that third implantation site 32 comprises papillarymuscle 72 by way of illustration and not limitation, and that thirdimplantation site 32 may comprise any potion of a wall of the rightventricle (e.g., a portion of tissue of the annulus at the ventricularsurface of tricuspid valve 4, a portion of the wall of the ventricle inthe vicinity of tricuspid valve 4, a portion of tissue in the vicinityof the apex of heart 2, or any other suitable portion of the wall of theventricle).

Reference is now made to FIGS. 2A-B and 6. First, second, and thirdtissue-engaging elements 60 a-c of FIG. 6 are implanted in cardiactissue in a manner as described hereinabove with reference to FIGS.2A-B, with the exception that, in order to implant third tissue-engagingelement 60 c, catheter 22 passes through the leaflets of tricuspid valve4 into the right ventricle and implants third tissue-engaging element 60c in tissue of the ventricle. Following coupled of third tissue-engagingelement 60 c in FIG. 6, second stent 50 b is deployed in secondimplantation site 52 in inferior vena cava 8, as described hereinabovewith reference to FIG. 2B.

Reference is now made to FIGS. 3A-C and 6. It is to be noted, that forsome applications, second longitudinal member 42 b is coupled at aproximal end thereof to one or more barbs 114 (i.e., and is notconnected to second stent 50, as shown). Barbs 114 enable secondlongitudinal member 42 b to be coupled to stent 50 that is in connectionwith first longitudinal member 42 a, and thereby maintain tension onthird implantation site 32 and maintain coaptation of at least anteriorleaflet 14 and septal leaflet 12.

Reference is again made to FIG. 6. Such an application of at least onetissue-engaging element 60 in a portion of tissue of the ventricle ofheart 2, in some applications, facilitates independent adjustment oftricuspid valve 4 and a portion of the ventricle wall of heart 2. Thatis, for some application, geometric adjustment of the right ventricle toimprove its function is achieved.

For some applications, following the deploying of first, second, third,and fourth tissue-engaging elements 60 a-d (i.e., first and secondanchors 40 a and 40 b, and first and second stents 50 a and 50 b), (1) adistance between first and second tissue-engaging elements 60 a and 60 bis adjustable by first adjustable mechanism, and (2) a distance betweenthird and fourth tissue-engaging elements 60 c and 60 d is adjustable bya second adjustable mechanism, as described hereinbelow with referenceto FIG. 5A. In such applications, (1) a length of first longitudinalmember 42 a between first and second tissue-engaging elements 60 a and60 b may be adjusted by a first adjusting mechanism 150, as shown inFIG. 5A, and (2) a length of second longitudinal member 42 b betweenthird and fourth tissue-engaging elements 60 c and 60 d may be adjustedby a second adjusting mechanism 150, as shown in FIG. 5A or 5B.

Adjusting mechanisms 150 typically each comprise a mechanical elementwhich shortens a distance of respective longitudinal members 42 a and 42b. For some applications, adjustable mechanisms 150 may be permanentlycoupled to respective longitudinal members 42 a and 42 b (not shown) andeach comprise an adjusting element, e.g., a spool for looping portionsof longitudinal members 42 a and 42 b therearound, a crimping bead forcrimping and shortening respective portions of longitudinal members 42 aand 42 b, a ratchet element, or a deforming element which deformsrespective portions of longitudinal members 42 a and 42 b in order toshorten its length between the respective tissue-engaging elements 60.For other applications, system 700 comprises an adjusting mechanismcomprising only an adjusting tool (not shown). In such applications, theadjusting tool may comprise an adjusting element, e.g., a crimping beadfor crimping and shortening respective portions of longitudinal members42 a and 42 b, or a deforming element which deforms respective portionsof longitudinal members 42 a and 42 b. In either application, a level ofregurgitation of tricuspid valve 4 may be monitored and the adjustmentof the geometry of the right ventricle is monitored during (1) theadjusting of the distance between first and second implantation sites 30and 52, and (2) the adjusting of the distance between third and secondimplantation sites 32 and 52, respectively.

Reference is now made to FIGS. 8 and 9, which are schematicillustrations of a system 800 for repairing tricuspid valve 4, inaccordance with respective applications of the present invention. Asshown in FIGS. 8 and 9, system 800 comprises first, second, third, andfourth tissue-engaging elements 60 a, 60 b, 60 c, and 60 d. System 800is similar in some respects to system 110 described hereinabove withreference to FIGS. 3A-B, with the exception that system 800 typicallycomprises only exactly one longitudinal member 42. Typically,longitudinal member 42 is directly coupled to first tissue-engagingelement 60 a, and indirectly coupled to tissue-engaging elements 60 cand 60 d by a longitudinal sub-member 802. Typically, one end oflongitudinal sub-member 802 is coupled to tissue-engaging element 60 c,and the other end of the sub-member is coupled to tissue-engagingelement 60 d. For some applications, as shown, longitudinal member 42 isnot fixed to longitudinal sub-member 802; instead, longitudinalsub-member 802 engages, e.g., is hooked on or looped over, longitudinalmember 42, at a junction 804 during deployment of the longitudinalsub-member. Alternatively, a ring is provided that couples thelongitudinal sub-member to the longitudinal member (configuration notshown).

For some applications, as shown in FIG. 8, a superior vena cava approachis used to implant system 800, in which tissue-engaging elements 60 a,60 c, and 60 d are advanced into atrium 6 via superior vena cava 10, andtissue-engaging element 60 b is deployed in the superior vena cava. FIG.9 illustrates an inferior vena cava approach, in which tissue-engagingelements 60 a, 60 c, and 60 d are advanced into atrium 6 via inferiorvena cava 8, and tissue-engaging element 60 b is deployed in theinferior vena cava. Typically, one of tissue-engaging elements 60 a, 60c, and 60 d is deployed at the septal side of tricuspid valve 4 in thecaudal part of the base of the septal leaflet, and the other two oftissue-engaging elements 60 a, 60 c, and 60 d are deployed at the muralside of the valve, dividing the entire mural side in three equal spaces,generally at the middle of anterior leaflet and the commissure betweenthe anterior and posterior leaflets. For some applications, yet anothertissue-engaging element is deployed at the mural side of the valve(configuration not shown).

An anchor-deployment tube is deployed into atrium 6, for example, usingtechniques described hereinabove with reference to FIG. 1A. Firsttissue-engaging element 60 a is deployed at first implantation site 30,such as using anchoring techniques described herein. First implantationsite 30 includes a portion of cardiac tissue in the vicinity oftricuspid valve 4 (e.g., a first portion of tissue of the annulus oftricuspid valve 4, as shown). For example, in the approach shown in FIG.8, first implantation site 30 may be on the mural side of the annulus ofthe valve (e.g., at anterior leaflet 14), approximately centered betweentwo of the commissures of the valve. In the approach shown in FIG. 9,first implantation site 30 may be on the mural side of the annulus(e.g., at posterior leaflet 16), approximately centered between two ofthe commissures of the valve. Alternatively, although typically lessdesirable, first implantation site 30 may be approximately at acommissure of the valve.

During the implantation using system 800, the distal end of theanchor-deployment tube is advanced to third implantation site 32. Thirdtissue-engaging element 60 c is deployed at third implantation site 32,such as using anchoring techniques described herein. Third implantationsite 32 includes a portion of cardiac tissue in the vicinity oftricuspid valve 4 (e.g., a second portion of tissue of the annulus oftricuspid valve 4, as shown). For example, in the approach shown in FIG.8, third implantation site 32 may be on the mural side of the annulus ofthe valve (e.g., at posterior leaflet 16), approximately centeredbetween two of the commissures of the valve. In the approach shown inFIG. 9, third implantation site 32 may be on the mural side of theannulus of the valve (e.g., at anterior leaflet 14), approximatelycentered between two of the commissures of the valve. Alternatively,although typically less desirable, third implantation site 32 may beapproximately at a commissure of the valve.

Subsequently to implantation at third implantation site, the distal endof the anchor-deployment tube is advanced to a fourth implantation site34. As mentioned above, longitudinal sub-member 802 extends betweentissue-engaging elements 60 c and 60 d. As fourth tissue-engagingelement 60 d is brought to fourth implantation site 34, longitudinalsub-member 802 engages, e.g., becomes hooked on or looped over,longitudinal member 42 at junction 804. Fourth tissue-engaging element60 d is deployed at fourth implantation site 34, such as using anchoringtechniques described herein. Fourth implantation site 34 includes aportion of cardiac tissue in the vicinity of tricuspid valve 4 (e.g., asecond portion of tissue of the annulus of tricuspid valve 4, as shown).For example, in the approaches shown in FIGS. 8 and 9, fourthimplantation site 34 may be on septal side of the annulus of the valve(e.g., at the caudal part of the base of septal leaflet 12,approximately centered between two of the commissures of the valve.Alternatively, although typically less desirable, fourth implantationsite 34 may be approximately at a commissure of the valve.

Following implantation at fourth implantation site 34, theanchor-deployment tube is withdrawn into the vena cava. Secondtissue-engaging element 60 b (stent 50) pulls on longitudinal member 42,which directly pulls on first tissue-engaging element 60 a, andindirectly pulls on tissue-engaging elements 60 c and 60 d vialongitudinal sub-member 802. Responsively, a distance between theleaflets of tricuspid valve 4 is adjusted to reduce and eliminateregurgitation through and thereby repair tricuspid valve 4. For someapplications, during the pulling of longitudinal member 42, a level ofregurgitation of tricuspid valve 4 is monitored. Longitudinal member 42is pulled until the regurgitation is reduced or ceases. Once thephysician determines that the regurgitation of tricuspid valve 4 isreduced or ceases, and tricuspid valve 4 has been repaired, secondtissue-engaging element 60 b (e.g., stent 50) is deployed from theanchor-deployment tube in the vena cava, such as described hereinabove,thereby implanting the tissue-engaging element at second implantationsite 52, as shown in FIGS. 8 and 9.

For some applications, stent 50 comprises a plurality of interconnectedsuperelastic metallic struts, such as described hereinabove withreference to FIG. 1D.

For some applications, following the implantation the tissue-engagingelements at their respective implantation sites, as describedhereinabove, a length of longitudinal member 42 is adjusted by anadjustable mechanism, as described hereinabove with reference to FIG. 5Aor 5B. Adjusting mechanism 150 typically comprises a mechanical elementwhich shortens a length of longitudinal member 42. For someapplications, adjustable mechanism 150 may be permanently coupled tolongitudinal member 42; mechanism 150 comprises an adjusting element,e.g., a spool for looping a portion of longitudinal member 42therearound, a crimping bead for crimping and shortening the portion oflongitudinal member 42, a ratchet element, or a deforming element whichdeforms the portion of longitudinal member 42. For other applications,system 800 comprises an adjusting mechanism comprising only an adjustingtool. In such applications, the adjusting tool may comprise an adjustingelement, e.g., a crimping bead for crimping and shortening the portionof longitudinal member 42, or a deforming element which deforms theportion of longitudinal member 42. In either application, a level ofregurgitation of tricuspid valve 4 may be monitored during the adjustingof the length of longitudinal member 42.

Reference is now made to FIGS. 10A-D, which are schematic illustrationsof tissue anchors 40, in accordance with respective applications of thepresent invention. One or more of these anchors may be used as anchors40 in the applications described hereinabove with reference to FIGS.1A-D, 2A-B, 3A-C, 5A-B, 6, 8, 9, 11A-C, 12A-C, 13C, and/or 14C.

In the configuration shown in FIG. 10A, anchor 40 comprises a distaltissue-piercing tip 972 fixed to a plurality of arms 974, which extendfrom tip 972 in respective generally distal and radially-outwarddirections. The arms are inserted entirely into the tissue, therebyhelping to couple the anchor to the tissue. For some applications, agreatest width W1 of anchor 40 is at least 6.5 mm, no more than 39 mm,and/or between 6.5 and 39 mm, such as 13 mm. For some applications, alength L2 of anchor 40, measured along an axis of the anchor from tipsof arms 974 to the end of tip 972 of the anchor, is at least 5 mm, nomore than 30 mm, and/or between 5 and 30 mm, such as 10 mm. For someapplications, a greatest diameter D1 of tip 972 is at least 1 mm, nomore than 6 mm, and/or between 1 and 6 mm, such as 2 mm.

In the configurations shown in FIGS. 10B and 10C, anchor 40 isconfigured to radially contract and expand in a manner generally similarto that of an umbrella (but without the umbrella cloth). The anchor isinserted into the tissue in a radially-contracted (closed) state, and istransitioned to a radially-expanded (open) state, either automaticallyor by the surgeon, in order to fix the anchor within the tissue. Forsome applications, such as shown in FIG. 10B, the anchor is configuredto assume the radially-expanded state when resting; the anchor is heldin a radially-contracted state during deployment, and transitions to theradially-expanded state upon being released. For other applications,such as shown in FIG. 10C, the anchor is configured to assume theradially-contracted state when resting; the anchor is deployed in theradially-contracted state, and is actively transitioned to theradially-expanded state by the surgeon after being inserted into thetissue.

Anchor 40 comprises distal tissue-piercing tip 972, which is fixed at adistal end of a post 976 (which typically comprises a tube). The anchorfurther comprises a plurality of ribs 978 (e.g., three or four). Ribs978 are coupled to the anchor near distal tip 972, such that the ribscan articulate with post 796, thereby changing respective angles betweenthe ribs and the post. The anchor further comprises a runner 980 (whichtypically comprises a tube), which is slidably coupled to post 976, suchthat the runner can slide along the post. A plurality of stretchers 982are coupled to runner 980 and respective ones of the ribs, such thatstretchers can articulate with the runner and the respective ribs. Eachof the stretchers may comprise one or more elongated elements; by way ofexample, each of the stretchers is shown comprising two elongatedelements. Typically, tips 984 of ribs 978 (i.e., at the ends not coupledto the anchor) are blunt.

For some applications, such as the configuration shown in FIG. 10B, theanchor at least partially comprises a shape-memory alloy (e.g.,nitinol), and the anchor's natural, resting state is theradially-expanded (open) state. The anchor is crimped inside a catheterso that it remains radially-contracted (closed) until deployed. Oncedeployed into the tissue, the catheter is pulled back and the anchor isallowed to open (i.e., automatically transition to the radially-expandedstate).

For some applications, in order to allow retraction of the anchor (suchas if the anchor has been improperly positioned, or needs to be removedfor another reason), the proximal end of runner 980 (i.e., the endfarther from tip 972) is removably coupled to an inner tube positionedwithin the catheter. For example, an outer surface of the proximal endof runner 980 and an inner surface of the inner tube near a distal endthereof may be threaded, to enable the removable coupling. Runner 980thus remains coupled to the inner tube until released, such as byrotating the inner tube with respect to the runner (the tissue preventsthe runner from also rotating). In order to retract the anchor, post 976is pushed in a distal direction while the runner is still coupled to theinner tube, thereby moving post 976 with respect to runner 980 andtransitioning the anchor back to its radially-contracted (closed) state.The anchor can thus be withdrawn into the catheter, repositioned, anddeployed again at a different location. The surgeon rotates the innertube to decouple the anchor once the location of the anchor has beenfinalized.

For some applications, in the configuration shown in FIG. 10C, anchor 40further comprises a tube positioned around post 976, proximal to runner980 (i.e., farther from tip 972). The tube is used to push runner 980 ina distal direction (toward the tip), in order to open the umbrella.

For some applications, a greatest width W2 of anchor 40, when radiallyexpanded, is at least 6.5 mm, no more than 39 mm, and/or between 6.5 and39 mm, such as 13 mm. For some applications, a length L3 of anchor 40,measured along an axis of the anchor from tips 984 of ribs 978 to theend of tip 972 of the anchor when the anchor is radially expanded, is atleast 5 mm, no more than 30 mm, and/or between 5 and 30 mm, such as 10mm. For some applications, a greatest diameter D2 of tip 972 is at least0.4 mm, no more than 2.4 mm, and/or between 0.4 and 2.4 mm, such as 0.8mm. For some applications, a greatest diameter D3 of post 976 is atleast 0.3 mm, no more than 1.8 mm, and/or between 0.3 and 1.8 mm, suchas 0.6 mm. For some applications, each of ribs 978 has a length of atleast 6 mm, no more than 20 mm, and/or between 6 and 20 mm, such as 10mm.

In the configuration shown in FIG. 10D, anchor 40 is barbed. Forexample, the anchor may be generally flat, and is shaped so as to defineone or more barbs 990, which typically extend from both sides of theanchor. The barbs help couple the anchor to the tissue. For someapplications, a greatest width W3 of anchor 40, excluding barbs 990, isat least 0.85 mm, no more than 5.1 mm, and/or between 0.85 and 5.1 mm,such as 1.7 mm. For some applications, a greatest width W4 of anchor 40,including barbs 990, is at least 1.25 mm, no more than 7.5 mm, and/orbetween 1.25 and 7.5 mm, such as 2.5 mm. For some applications, a lengthL4 of anchor 40, measured along an axis of the anchor from a distal endof the barbed portion to the proximal tip of the anchor, is at least 5mm, no more than 30 mm, and/or between 5 and 30 mm, such as 9.5 mm. Forsome applications, a greatest thickness T of anchor 40 is at least 0.1mm, no more than 0.6 mm, and/or between 0.1 and 0.6 mm, such as 0.2 mm.

Reference is now made to FIGS. 11A-C, which are schematic illustrationsof a delivery tool system 1000 for implanting anchor 40, in accordancewith some applications of the present invention. Delivery tool system1000 may be used, for example, to rotate, locate, place, and implant ananchor in combination with the applications described herein withreference to FIGS. 1A-D, 2A-B, 3A-C, 5A-B, 6, 8, 9, 13A-C, 14A-C, 15A-B,16A-B, and 17. Although longitudinal member 42 is shown in FIGS. 11A-Cas being fixed to stent 50, this is not necessarily the case, and toolsystem 200 thus may also be used in combination with the applicationsthat do not utilize stent 50, such as those described herein withreference to FIGS. 3C and 5A-B.

FIG. 11A shows an exploded view of some of the components of deliverytool system 1000 and its spatial orientation relative to stent 50,longitudinal member 42, and anchor 40. In such an application,longitudinal member 42 comprises a plurality of fibers aligned so as toform a band 1140. Band 1140 is coupled at a first portion 1141 thereof(e.g., a proximal portion, as shown) to a portion of stent 50. Stent 50comprises a plurality of mechanical structural elements 1651 arranged soas to form a tubular structure of stent 50 in a radially-expanded stateof stent 50. First portion 1141 of band 1140 is coupled to the portionof stent 50 via a tension-distributing element 1160, as will bedescribed hereinbelow with reference to FIGS. 13A-C, 14A-C, and 15A-B.

A second portion 1143 of band 1140 is coupled to tissue anchor 40 via aconnecting element 1240 that is coupled to a proximal portion of anchor40 via an adapter head 1230. Tissue anchor 40 comprises a helical tissueanchor having a central lumen about a longitudinal axis 1155. Connectingelement 1240 is shaped so as to define aflexible-longitudinal-member-coupler 1242 at a proximal portion ofconnecting element 1240. Flexible-longitudinal-member-coupler 1242 isshaped so as to define an opening 1244 configured for coupling of secondportion 1143 of band 1140 to connecting element 1240. Typically secondportion 1143 of band 1140 is coupled to connecting element 1240 bythreading it through opening 1244 and forming a distal loop 1142.

Connecting element 1240 is shaped so as to provide an annular loop 1246at a portion of element 1240 that is distal to opening 1244 andflexible-longitudinal-member-coupler 1242. Annular loop 1246 has aninner diameter that is larger than an outer diameter of the anchor 40.Annular loop 1246 surrounds the proximal-most coil in a manner whichfacilitates rotation of anchor 40 about axis 1155 freely by facilitatingrotation of the proximal-most loop of anchor 40 freely about axis 1155.For some applications loop 1246 rotates around the proximal portion ofanchor 40.

Adapter head 1230 is shaped so as to define a distal tissue-anchorcoupling element 1233 which has an outer diameter that is equal to orless than a diameter of the lumen of anchor 40 in a manner in whichtissue-anchor coupling element 1233 fits within the lumen of anchor 40and is welded to a proximal portion of anchor 40 in order to coupleadapter head 1230 to anchor 40 (as shown hereinbelow with reference toFIGS. 12A-C). Adapter head 1230 is shaped so as to define an annularelement 1234 which has an outer diameter that is larger than a diameterof an opening provided by annular loop 1246. Thus, adapter head 1230prevents decoupling of connecting element 1240 from anchor 40 sinceconnecting element 1240 is not welded to anchor 40.

System 1000 comprises a torque-delivering tool comprising atorque-delivering cable 1204 that is slidably disposed within a lumen ofa tube 1202. Torque-delivering cable 1204 is welded at a distal endthereof to a first coupling 1220 shaped so as to define a male couplingelement 1222. Adapter head 1230 is shaped so as to provide a secondcoupling 1232 shaped so as to define a female coupling elementconfigured to fit the male coupling element 1222. When coupled together,as will be described hereinbelow with reference to FIGS. 12A-C, firstand second couplings 1220 and 1232, respectively, coupletorque-delivering cable 1204 to tissue anchor 40. Torque-deliveringcable 1204 is rotated in order to rotate first coupling 1220 and secondcoupling 1232 of adapter head 1230, and thereby tissue anchor 40.

Since adapter head 1230, having second coupling 1232, is welded to aproximal portion of anchor 40, when adapter head 1230 is rotated, anchor40 is rotated. As anchor 40 is rotated, the proximal-most coil of anchor40 rotates freely within annular loop 1246, and anchor 40 rotates withrespect to annular loop 1246.

As shown, the proximal portion of connecting element 1240 comprisingflexible-longitudinal-member-coupler 1242, shaped so as to defineopening 1244, is generally crescent-shaped. A portion of tube 1202 in avicinity of distal end 1205 of tube 1202 is coupled to ananti-entanglement device 1224 which is shaped so as to define a distalelement 1226 that is generally crescent-shaped. Distal element 1226 isdisposed alongside the proximal portion of connecting element 1240 in amanner in which the crescent shaped are aligned, as shown in FIG. 11B.In such a configuration, during rotation of torque-delivering cable 1204to rotate anchor 40, tube 1202 is not rotated around cable 1204, but isheld in place, which (1) keeps anti-entanglement device 1224 maintainedin a relative position with reference to connecting element 1240, andthereby (2) connecting element 1240 is not rotated as anchor 40 isrotated, and flexible member 42 (or band 1140, in this application) isnot rotated when anchor is rotated. In such a manner, as anchor 40rotates with respect to annular loop 1246, anchor 40 rotates withrespect to flexible member 42, thus anti-entanglement device 1224prevents band 1140 from entangling during rotation of anchor 40.

As shown in FIG. 11B, tissue anchor 40 defines first tissue-engagingelement 60 a, and stent 50 defines second tissue-engaging element 60 b.

Reference is now made to FIG. 11C which shows a tool 1002 forfacilitating implanting of tissue anchor 40 and expansion of stent 50within the blood vessel of the patient. Tool 1002 comprises a proximalhandle portion 1004 which is coupled to a proximal portion of a firstshaft 1016. As shown in the enlarged cross-sectional image on themiddle-right of FIG. 11C, stent 50 crimped within a sheath 1190. Aproximal portion of stent 50 is shaped so as to define two or moredelivery-tool couplers 1159. A distal end of first shaft 1016 is shapedso as to provide one or more stent-couplers 1017. A respective deliverytool coupler 1159 is coupled to shaft 1016 by being coupled to arespective stent coupler 1017. When sheath 1190 surrounds stent 50,stent 50 is maintained in a crimped state and couplers 1159 remaincoupled to couplers 1017. As shown, tube 1202 and torque-deliveringcable 1204 pass through a lumen of stent 50 in its crimped, orradially-compressed state.

As described hereinabove, tissue anchor 40 defines first tissue-engagingelement 60 a and stent 50 defines second tissue-engaging element 60 b.As described hereinabove, tissue anchor 40 is implanted in tissue of thepatient prior to positioning stent 50 in the blood vessel of thepatient. That is, tissue anchor 40 is exposed from within sheath 1190and implanted in tissue of the patient while stent 50 remains crimpedwithin sheath 1190. Since torque-delivering cable 1204 and tube 1202pass through the lumen of stent 50, during rotation of anchor 40, anchor40 rotates with respect to stent 50 while stent remains static.

Tool 1002 comprises a “Y”-shaped connector 1014 coupled to a proximalend of shaft 1016. A first arm of connector 1014 provides a lumen forpassage of a guidewire tube 1013 that is configured to hold a guidewire(not shown). A second arm of connector 1014 provides a lumen for passageof tube 1202 that surrounds torque-delivering cable 1204. As shown inthe cross-sectional image on the top-right, tube 1202 surrounding cable1204 passes alongside guidewire tube 1013. Guidewire tube 1013 extendsthrough tool 1002 and through a lumen provided by a distal atraumatictip 1192. For such an application, tip comprises a symmetrical tip 1196.Tip 1192 enables atraumatic advancement the shafts of tool 1002 throughvasculature of the patient. Tip 1192 comprises a flexible biocompatiblematerial, e.g., polyurethane, and a radiopacity-enhancing material suchas an embedded marker made from a radiopaque substance such as Pt—Ir, oralternatively by adding BaSO4 to the biocompatible material.

Reference is now made to FIGS. 18A-B, which are schematic illustrationsof atraumatic tip 1192 comprising an asymmetrical atraumatic tip 2000having an asymmetrical body 1198, in accordance with some applicationsof the present invention. As shown, tip 2000 is shaped so as to providea lumen for passage therethrough of guidewire tube 1013. Tip 2000 isshaped so as to define a recess 2002 for housing anchor 40 during theadvancement of the shafts of tool 1002 through the vasculature of thepatient. Anchor 40, flexible-longitudinal-member-coupler 1242, band1140, and guidewire tube 1013 are shown in phantom to indicate theirpositioning relative to tip 2000. Once the physician wishes to releaseanchor 40 from within recess 2002, the physician pushes on guidewiretube 1013 so as to disengage tip 2000 from distal end 1191 of sheath1190 (shown in FIG. 11C) and distance tip 2000 and anchor 40 from distalend 1191. The physician then pulls proximally on cable 1204 so as toretract anchor 40 from within recess 2002. Once anchor 40 is exposedfrom within recess 2002, anchor 40 may be rotated, as describedhereinabove with reference to FIGS. 11C and 12A, and may be disengagedfrom first coupling 1220, as described hereinabove with reference toFIGS. 11C and 12B-C.

Reference is again made to FIG. 11C. The shafts of tool 1002 are guidedalong the guidewire (not shown for clarity of illustration) to therespective implantation sites of anchor 40 and stent 50. During theadvancement of the shafts through the vasculature, tip 1192 is coupledto a distal end 1191 of sheath 1190 (e.g., by having a proximal portionof tip 1192 disposed within a lumen of sheath 1190 at distal end 1191thereof. Prior to deployment and implantation of anchor 40 from withinsheath 1190, tip 1192 is pushed distally so as to decouple tip 1192 fromdistal end 1191 of sheath 1190. Tip 1192, for some applicationscomprises symmetrical tip 1196. Symmetrical tip 1196 facilitatesrecoupling of tip 1192 to distal end 1191 of sheath 1190 following thedecoupling of tip 1192 from sheath 1190.

Reference is now made to FIGS. 12A-C, which are schematic illustrationsof first and second couplings 1220 and 1232, respectively, in theirlocked state (FIG. 12A) and their unlocked state (FIG. 12C), inaccordance with some applications of the present invention. As describedhereinabove, first coupling 1220 matingly engages second coupling 1232when a distal end 1205 of tube 1202 surrounding torque-delivering cable1204 is disposed distally. When distal end 1205 is disposed distally, asshown in FIG. 12A, a distal portion of tube 1202 surrounds first andsecond couplings 1220 and 1232, respectively, in a manner which keepsfirst and second couplings 1220 and 1232, respectively, coupledtogether. As shown in FIG. 12A, and as described hereinabove, the distalportion of tube 1202 is coupled to anti-entanglement device 1224. Asshown in the cross-sectional images of FIGS. 12A-C, distal element 1226of anti-entanglement device 1224 is disposed behindflexible-longitudinal-member-coupler 1242 at the proximal portion ofconnecting element 1240.

Reference is now made to FIGS. 11C and 12A. As shown in FIG. 11C, tool1002 comprises a steering mechanism 1018 that surrounds shaft 1016 andis coupled to a proximal end 1193 of sheath 1190. Steering mechanism1018 facilitates proximal and distal movement of a steering wire (notshown for clarity) with respect to mechanism 1018, tube 1202, andguidewire tube 1013. Steering mechanism 1018 comprises a user-engagingelement 1195 which enables the physician to facilitate steering ofsheath 1190. Steering mechanism 1018 comprises an actuating mechanism1194 comprising a plurality of teeth which facilitate proximal anddistal movement of the steering wire when user-engaging element 1195 isactuated by the physician using system 1000.

When the physician wishes to expose anchor 40 from within sheath 1190,the physician slides the cable 1204 and tube 1202 together so as toexpose anchor 40. For some applications, cable 1204 and tube 1202 areslid when the physician pushes at least handle portion 1004 so as topush tube 1202 (and cable 1204 disposed therein) distally in order topush anchor 40 distally within sheath 1190 and expose anchor 40 fromwithin sheath 1190. During the sliding, mechanism 1018 is held in placeso as to prevent distal sliding of sheath 1190 during the distal slidingof anchor 40. (When the physician desires to deploy stent 50, thephysician slides sheath 1190 proximally by sliding mechanism 1018 withrespect to shaft 1016 so as to expose stent 50. For such applications,stent 50 is exposed from within sheath 1190 and is allowed to expandradially and disengage delivery-tool couplers 1159 of stent 50 fromstent-couplers 1017 of tool 1002).

When the physician wishes to position anchor 40 into the correctanatomical place such as the anteroposterior commissure, the physicianactuates user-engaging element 1195 to actuate steering mechanism 1018which pulls the steering cable, causing steering of sheath 1190 in orderto deflect sheath 1190 in one direction. The physician may then rotatethe handle portion of mechanism 1018 to change the deflection directionand reach the correct anatomical positioning of anchor 40.

As shown in FIG. 11C, proximal handle portion 1004 comprises ananchor-deployment actuator 1006 and a holder 1008. Actuator 1006, asshown in the cross-sectional image, is coupled to torque-deliveringcable 1204 such that when first and second couplings 1220 and 1232,respectively, are coupled together (as shown in FIG. 12A), rotation ofactuator 1006 rotates torque-delivering cable 1204 in order to rotateanchor 40. Typically, anchor 40 is rotated once anchor 40 is exposedfrom within sheath 1190, as described hereinabove, in order to screwanchor 40 into tissue of the patient.

Holder 1008 is coupled to a proximal portion of tube 1202 that surroundscable 1204. Holder 1008 is shaped so as to define a proximal recess1009, with transverse holes 1011. Actuator 1006 is shaped so as todefine a distal protrusion 1007 which is shaped so as to fit withinrecess 1009 of holder 1008.

As shown in FIGS. 11C and 12A, the distal portion of tube 1202 disposedaround first and second couplings 1220 and 1232, respectively. In such aconfiguration, protrusion 1007 of actuator 1006 is disposed proximallyto holder 1008. Furthermore, holder 1008 comprises a safety 1010 (e.g.,a suture which extends transverse to the longitudinal lumen of recess1009 through holes 1011) which prevents protrusion 1007 from slidingwithin recess 1009 of holder 1008.

When the physician desires to disengage first and second couplings 1220and 1232, respectively, the physician releases safety 1010 (e.g., bycutting the suture) and pushes actuator 1006 distally so that protrusion1007 of actuator 1006 slides within recess 1009 of holder 1008. Duringthe pushing of actuator 1006, the physician holds holder 1008.Responsively, since actuator 1006 is coupled to cable 1204, cable 1204is slid distally (in the direction as indicated by arrow 2) so thatfirst and second couplings 1220 and 1232, respectively, are exposed fromwithin the distal portion of tube 1202. Additionally, since tissueanchor 40 is implanted in tissue of the patient, the tissue exerts aforce on tube 1202 which pushes tube 1202 proximally, in the directionas indicated by arrow 1. Consequently, first and second couplings 1220and 1232, respectively, are exposed from within the distal portion oftube 1202, as shown in FIG. 12B.

As shown in FIG. 12C, the physician tilts tube 1202 (e.g., clockwise, asshown) in order to disengage male coupling element 1222 of firstcoupling 1220 from the female coupling element of second coupling 1232.Thereby, tool 1002 is disengaged from anchor 40. Following thedisengaging of tool 1002 from anchor 40, anchor 40, adapter head 1230,and connecting element 1240 remain implanted at the implantation site.

Following the implantation of tissue anchor 40 at first implantationsite 30, sheath 1190 is retracted proximally by pulling proximallymechanism 1018 so as to expose band 1140 coupled to tissue anchor 40.Sheath 1190 is navigated by mechanism 1194 such that distal end 1191 ofsheath 1190 is positioned in second implantation site 52. As tool 1002is navigated, tension is applied to band 1140 in order to draw togetherfirst and second implantation sites 30 and 52, respectively, and repairtricuspid valve 4, in a manner as described hereinabove with referenceto FIGS. 1A-D.

For some applications, during the pulling of band 1140 by tool 1002, alevel of regurgitation of tricuspid valve 4 is monitored and a parameterindicative of repair of tricuspid valve 4 is monitored. For example,leaflet anatomy during the opening and closing of tricuspid valve 4 isassessed using an imaging device such as intracardiac echocardiography,transthoracic echocardiography or transesophageal echocardiography. Forsome applications, during the monitoring, measurements used to assessthe efficiency of the procedure are evaluated pre-, during, andpost-procedure. For example, these measurements could include, but notexclusively, measuring the echocardiographic distance between theanteroposterior commissure and the rim at the junction of the inferiorvena cava and the right atrium, or measuring the echocardiographicregurgitant volume through tricuspid valve 4. Band 1140 is pulled untilthe regurgitation is reduced or ceases.

Once the physician determines that the regurgitation of tricuspid valve4 is reduced or ceases, and tricuspid valve 4 has been repaired, sheath1190 is retracted proximally as described hereinabove with reference toFIG. 1C by pulling proximally on sheath 1190, which is done by pullingproximally on mechanism 1018, so as to expose stent 50 from withinsheath 1190. As stent 50 expands radially, delivery-tool couplers 1159of stent 50 expand away and disengage from stent-couplers 1017 of tool1002, thereby disengaging stent 50 from tool 1002. Following thedisengaging of tool 1002 from stent 50, tool 1002 is extracted from thebody of the patient.

Reference is now made to FIGS. 13A-C, which are schematic illustrationsof a stent 1150 comprising a proximal portion 1156 and a distal portion1157, each of portions 1156 and 1157 comprising a plurality ofmechanical structural elements 1651 shaped so as to define a pluralityof peaks 1152, a plurality of valleys 1154, and a plurality ofinterconnectors 1158, in accordance with some applications of thepresent invention. FIG. 13A shows stent 1150 in an assembled state, andFIG. 13B shows stent 1150 in a flattened state in which stent 1150 iscut longitudinally and flattened, for clarity of illustration. It is tobe noted, however, that the configuration shown in FIG. 13A defines theconfiguration of stent 1150 in a radially-expanded state.

The structural configuration of stent 1150 provided by mechanicalstructural elements 1651 may be formed by expanding a laser-slottedmetallic tube, or may be chemically etched from a flat sheet and weldedto a tube, or may be formed from a single wire, or may be formed byassembling individual wire elements, or by any other method ofconstruction known to those skilled in the art. The design of stent 1150can be laser cut from a small diameter tube, expanded to the finaldiameter, or may be cut from a large diameter tube, which is equal tothe final diameter of a fully expanded stent or which may be furtherexpanded to an even larger diameter.

Stent 1150 is shaped so as to provide a plurality of coaxially-disposedannular ring portions 1151. Each ring portion 1151 is shaped so as todefine a plurality of peaks 1152 and a plurality of valleys 1154. Asshown, each of the plurality of interconnectors 1158 is orientedvertically. As shown in exemplary ring portions 1151 a and 1151 b, thering portions are aligned in a manner in which peaks 1152 and 1154 arein phase. Thus, interconnectors 1158 are vertically disposed betweenrespective valleys 1154 of respective ring portions 1151.

Such a configuration of mechanical structural elements 1651 providesstent 1150 with a property of generally maintaining its longitudinallength L5 measured along longitudinal axis 1155, during radial expansionof stent 1150 from a radially-compressed state of stent 1150.Additionally, such a configuration of mechanical structural elements1651 in distal portion 1157 of stent 1150 facilitates partialcompressibility retrievability/retractability into sheath 1190 (asdescribed hereinabove with reference to FIG. 11C) of distal portion 1157following radial expansion of distal portion 1157. That is, sheath 1190is slidable proximally to expose distal portion 1157 from within thesheath and allow distal portion 1157 to radially expand while proximalportion 1156 remains disposed radially-compressed within sheath 1190.Since (1) peaks 1152 of distal portion 1157 all point distally, and (2)interconnectors 1158 connect valleys 1154 of distal portion 1157, thereis no portion of distal portion 1157 which protrudes from the tubularstructure of stent 1150, which would otherwise interfere with distalsliding of sheath 1190 to compress and retrieve/retract distal portion1157 within sheath 1190. Therefore, distal portion 1157 isretrievable/retractable within sheath 1190. As such stent 1150 isretrievable up to ½ deployment, as shown.

Each annular ring portion 1151 comprises a plurality of struts 1153.Each strut has a width W7 of between 50 and 1000 micron, e.g., between100 and 500 micron, for example, 200 micron. Each interconnector 1158has a width W6 of between 50 and 500 micron e.g., 200 micron.

Stent 1150 is shaped so as to provide a plurality of delivery-toolcouplers 1159 at a proximal end 1300 thereof, as described hereinabovewith reference to FIG. 11C. Couplers 1159 are shaped so as to surroundand engage a plurality of tabs, which may function as pawls, provided onshaft 1016 of tool 1002.

As shown in FIG. 13C, stent 1150 is coupled to flexible band 1140 at afirst portion thereof, i.e., a proximal portion thereof. Flexible band1140, in turn, is coupled at a second portion (i.e., a distal portionthereof) to tissue anchor 40. As described hereinabove with reference toFIGS. 1A-D, tissue anchor 40 is implanted in tissue of tricuspid valve4, then stent 50 is pulled in order to apply tension to flexible member42 in order to adjust the relative positioning of the leaflets oftricuspid valve 4, and then stent 50 is deployed in the blood vessel.Following the deploying of stent 50 in the blood vessel, flexible member42 exerts tension force on stent 50. In order to distribute tensionalong the length of stent 1150, stent 1150 is shaped so as to define atension-distributing element 1160.

Tension-distributing element 1160 has a width W5 of between 1 and 4 mm,e.g., 2.6 mm. Tension-distributing element 1160 has a longitudinallength L6 measured along longitudinal axis 1155 that is generally equalto longitudinal length L5 of stent 1150, as shown by way of illustrationand not limitation. Thus, tension-distributing element 1160, as shown inFIGS. 13A-C, comprises an elongate tension-distributing element 1161.That is, each one of lengths L5 and L6 of stent 1150 andtension-distributing element 1160, respectively, is between 20 and 120mm, e.g., 70 mm. It is to be noted that lengths L5 and L6 are shown asbeing generally equal by way of illustration and not limitation, andthat length L6 tension-distributing element 1160 may be smaller than thelongitudinal length of the stent, as shown hereinbelow with reference toFIGS. 15A-B, for example. That is, the longitudinal length oftension-distributing element 1160 is at least 15% of longitudinal lengthL5 of stent 1150.

Typically, a width of a widest mechanical structural element 1651 isbetween 100 and 500 micron, and width W5 of tension-distributing element1160 is between 1 and 4 mm. For some applications, width W5 oftension-distributing element 1160 is at least 13 times the width of thewidest mechanical structural element 1651.

Tension-distributing element 1160 is shaped so as to provide a pluralityof eyelets 1170 (FIGS. 13A-B). As shown in FIG. 13C, the proximalportion of flexible member 42 (or band 1140, as shown) is threadedthrough eyelets 1170 of tension-distributing element 1160. By threadingthe proximal portion of band 1140 through tension-distributing element1160, tension applied from anchor 40 and band 1140 is distributed alongthe length of stent 1150.

It is to be noted that tension-distributing element 1160 and mechanicalstructural elements 1651 are typically fabricated from a single piece oftubular alloy, typically superelastic, e.g., nitinol. For someapplications tension-distributing element 1160 and mechanical structuralelements 1651 are modularly assembled.

As shown in FIG. 13C, tissue anchor 40 defines first tissue-engagingelement 60 a, and stent 1150 defines second tissue-engaging element 60b.

Reference is now made to FIGS. 14A-C, which are schematic illustrationsof a stent 1400 comprising one or more (e.g., two, as shown) firstportions 1402 and one or more (e.g., one, as shown) second portion 1404,each of portions 1402 and 1404 comprising a plurality of mechanicalstructural elements 1651, in accordance with some applications of thepresent invention. FIG. 14A shows stent 1400 in an assembled state, andFIG. 14B shows stent 1400 in a flattened state in which stent 1400 iscut longitudinally and flattened, for clarity of illustration. It is tobe noted, however, that the configuration shown in FIG. 14A defines theconfiguration of stent 1400 in a radially-expanded state.

The structural configuration of stent 1400 provided by mechanicalstructural elements 1651 may be formed by expanding a laser-slottedmetallic tube, or may be chemically etched from a flat sheet and weldedto a tube, or may be formed from a single wire, or may be formed byassembling individual wire elements, or by any other method ofconstruction known to those skilled in the art. The design of stent 1400can be laser cut from a small diameter tube, expanded to the finaldiameter, or may be cut from a large diameter tube, which is equal tothe final diameter of a fully expanded stent or which may be furtherexpanded to an even larger diameter.

Portions 1402 of stent 1400 are each shaped so as to provide a plurality(e.g., two, as shown) of coaxially-disposed annular ring portions 1151.Each ring portion 1151 is shaped so as to define a plurality of peaks1152 and a plurality of valleys 1154. Stent 1400 comprises a pluralityof interconnectors 1158 (e.g., vertical interconnectors, as shown). Asshown in exemplary ring portions 1151 a and 1151 b, the ring portionsare aligned in a manner in which peaks 1152 and 1154 are in phase. Thus,interconnectors 1158 are vertically disposed between respective valleys1154 of respective ring portions 1151.

Portions 1402 have interconnectors 1158 a having a length of between 4and 25 mm, e.g., 9 mm. Portion 1404 is shaped so as to provide aplurality of elongate interconnectors 1158 b which connect portions1402. Interconnectors 1158 b have a length of between 20 and 80 mm,e.g., 50 mm. Taken together, peaks 1152, valleys 1154, andinterconnectors 1158 a of portions 1402 impart a greater radial force onsurrounding tissue in a radially-expanded state of stent 1400 thanportion 1404 of stent 1400, because portion 1404 comprises only elongateinterconnectors 1158 b. Such a configuration of stent 1400 provides anendoluminal implant which has a portion that exerts less radial force onsurrounding tissues, thus, stent 1400 is configured to be placed in ablood vessel (e.g., the inferior vena cava) that is surrounded byorgans. For applications in which stent 1400 is placed within the bloodvessel that is surrounded by organs, portion 1404 of stent 1400 exertsless radial force on the surrounding organs than portions 1402.

Such a configuration of mechanical structural elements 1651 providesstent 1400 with a property of generally maintaining its longitudinallength L5 measured along longitudinal axis 1155, during radial expansionof stent 1400 from a radially-compressed state of stent 1400.

Each annular ring portion 1151 comprises a plurality of struts 1153.Each strut has a width W7 of between 50 and 1000 micron, e.g., between100 and 500 micron, for example, 200 micron. Each interconnector 1158has a width W6 of between 50 and 500 micron e.g., 200 micron.

Stent 1400 is shaped so as to provide a plurality of delivery-toolcouplers 1159 at a proximal end 1300 thereof, as described hereinabovewith reference to FIG. 11C. Couplers 1159 are shaped so as to surroundand engage a plurality of tabs, which may function as pawls, provided onshaft 1016 of tool 1002.

As shown in FIG. 14C, stent 1400 is coupled to flexible band 1140 at afirst portion thereof, i.e., a proximal portion thereof. Flexible band1140, in turn, is coupled at a second portion (i.e., a distal portionthereof) to tissue anchor 40. As described hereinabove with reference toFIGS. 1A-D, tissue anchor 40 is implanted in tissue of tricuspid valve 4(e.g., in the anteroposterior commissure), then stent 50 is pulled inorder to apply tension to flexible member 42 (or band 1140) in order toadjust the relative positioning of the leaflets of tricuspid valve 4,and then stent 50 is deployed in the blood vessel. Following thedeploying of stent 50 in the blood vessel, flexible member 42 exertstension force on stent 50. In order to distribute tension along thelength of stent 1400, stent 1400 is shaped so as to definetension-distributing element 1160.

As shown in FIG. 14B, tension-distributing element 1160 comprises amodular tension-distributing element having a distaltension-distributing element 1162 a and a proximal tension-distributingelement 1162 b. Distal tension-distributing element 1162 a and proximaltension-distributing element 1162 b are coupled together by aninterconnector 1158 b. Distal tension-distributing element 1162 a andproximal tension-distributing element 1162 b, together withinterconnector 1158, assume length L6 of tension-distributing element1160 that is generally equal to longitudinal length L5 of stent 1400, asshown by way of illustration and not limitation. Each one of lengths L5and L6, respectively, is between 20 and 120 mm, e.g., 70 mm. It is to benoted that lengths L5 and L6 are shown as being generally equal by wayof illustration and not limitation, and that length L6tension-distributing element 1160 may be smaller than the longitudinallength of the stent, as shown hereinbelow with reference to FIGS. 15A-B,for example. That is, the longitudinal length of tension-distributingelement 1160 is at least 15% of longitudinal length L5 of stent 1400.

Each one of distal tension-distributing element 1162 a and proximaltension-distributing element 1162 b has a longitudinal length L7 ofbetween 5 and 25 mm.

As shown in FIG. 14C, first portion 1143 of band 1140 is coupled todistal tension-distributing element 1162 a by being threaded througheyelet 1170 of element 1162 a. It is to be noted, however, that portion1143 of band 1140 may be coupled to both distal tension-distributingelement 1162 a and proximal tension-distributing element 1162 b byextending along the longitudinal length of stent 1400. It is to be notedthat longer the portion of band 1140 coupled along the longitudinallength of stent 1400, the more force is distributed along thelongitudinal length of stent 1400.

It is to be noted that tension-distributing elements 1162 a and 1162 band mechanical structural elements 1651 are fabricated from a singlepiece of tubular alloy, typically superelastic, e.g., nitinol. For someapplications tension-distributing elements 1162 a and 1162 b andmechanical structural elements 1651 are modularly assembled.

As shown in FIG. 14C, tissue anchor 40 defines first tissue-engagingelement 60 a, and stent 1400 defines second tissue-engaging element 60b.

Reference is now made to FIGS. 15A-B, which are schematic illustrationsof a stent 1500 comprising a first portion 1502, a second portion 1504,and a third portion 1506, each of portions 1502, 1504, and 1506comprising a plurality of mechanical structural elements 1651, inaccordance with some applications of the present invention. FIG. 15Ashows stent 1500 in an assembled state, and FIG. 15B shows stent 1500 ina flattened state in which stent 1500 is cut longitudinally andflattened, for clarity of illustration. It is to be noted, however, thatthe configuration shown in FIG. 15A defines the configuration of stent1500 in a radially-expanded state.

The structural configuration of stent 1500 provided by mechanicalstructural elements 1651 may be formed by expanding a laser-slottedmetallic tube, or may be chemically etched from a flat sheet and weldedto a tube, or may be formed from a single wire, or may be formed byassembling individual wire elements, or by any other method ofconstruction known to those skilled in the art. The design of stent 1500can be laser cut from a small diameter tube, expanded to the finaldiameter, or may be cut from a large diameter tube, which is equal tothe final diameter of a fully expanded stent or which may be furtherexpanded to an even larger diameter.

Portion 1504 comprises a plurality of struts 1520 each having a width W9of between 25 and 250 micron, e.g., 100 micron. Struts 1520 arespatially arranged so as to form a plurality of quadrilateral-shapedopenings 1522, e.g., diamond-shaped openings.

Portion 1506 comprises a plurality of struts 1530 each having a widthW10 of between 50 and 500 micron, e.g., 200 micron. Struts 1530 arespatially arranged so as to form a plurality of peaks 1152 and valleys1154.

Struts 1520 of portion 1504 are longer and thinner than struts 1530 ofportion 1506. Thus, portion 1506 exerts a greater radial force onsurrounding tissue in a radially-expanded state of stent 1500 thanportion 1504 of stent 1500. Additionally, the relative spatialarrangement of struts 1530 of portion 1506 (as compared with therelative spatial arrangement of struts 1520 of portion 1504) enablesportion 1506 to exert a greater radial force on surrounding tissue thanportion 1504.

Portion 1502 of stent 1500 is shaped so as to provide a plurality (e.g.,two, as shown) of coaxially-disposed annular ring portions 1151. Eachring portion 1151 is shaped so as to define a plurality of peaks 1152and a plurality of valleys 1154. Stent 1400 comprises a plurality ofinterconnectors 1158 (e.g., vertical interconnectors, as shown). Asshown in exemplary ring portions 1151 a and 1151 b, the ring portionsare aligned in a manner in which peaks 1152 and 1154 are in phase. Thus,interconnectors 1158 are vertically disposed between respective valleys1154 of respective ring portions 1151.

Each one of interconnectors 1158 of portion 1502 has a length of between4 and 25 mm, e.g., 9 mm. Taken together, peaks 1152, valleys 1154, andinterconnectors 1158 of portions 1502 impart a greater radial force onsurrounding tissue in a radially-expanded state of stent 1500 thanportions 1504 and 1506 of stent 1500. Such a configuration of stent 1500provides an endoluminal implant which has one or more portions (e.g.,portions 1504 and 1506) that exert less radial force on surroundingtissues than portion 1502; thus, stent 1500 is configured to be placedin a blood vessel (e.g., the inferior vena cava) that is surrounded byorgans. For applications in which stent 1500 is placed within the bloodvessel that is surrounded by organs, portion 1504 of stent 1500 exertsless radial force on the surrounding organs than portion 1502.

Such a configuration of mechanical structural elements 1651 providesstent 1500 with a property of generally maintaining its longitudinallength L5 measured along longitudinal axis 1155, during radial expansionof stent 1500 from a radially-compressed state of stent 1500.

Each annular ring portion 1151 comprises a plurality of struts 1153.Each strut has a width W7 of between 50 and 1000 micron, e.g., between100 and 500 micron, for example, 200 micron. Each interconnector 1158has a width W6 of between 50 and 500 micron e.g., 200 micron.

Stent 1500 is shaped so as to provide a plurality of delivery-toolcouplers 1159 at a proximal end 1300 thereof, as described hereinabovewith reference to FIG. 11C. Couplers 1159 are shaped so as to surroundand engage a plurality of tabs, which may function as pawls, provided onshaft 1016 of tool 1002.

Stent 1500 is couplable to flexible band 1140 in a manner as describedhereinabove with reference to FIGS. 13A-C and 14A-C. Flexible band 1140,in turn, is coupled at a second portion (i.e., a distal portion thereof)to tissue anchor 40. As described hereinabove with reference to FIGS.1A-D, tissue anchor 40 is implanted in tissue of tricuspid valve 4(e.g., in the anteroposterior commissure), then stent 50 is pulled inorder to apply tension to flexible member 42 (e.g., band 1140) in orderto adjust the relative positioning of the leaflets of tricuspid valve 4,and then stent 50 is deployed in the blood vessel. Following thedeploying of stent 50 in the blood vessel, flexible member 42 exertstension force on stent 50. In order to distribute tension along thelength of stent 1500, stent 1500 is shaped so as to definetension-distributing element 1160.

As shown in FIG. 15B, tension-distributing element 1160 comprises adistal tension-distributing element 1163. Distal tension-distributingelement 1163 has a longitudinal length L11 of between 10 and 60 mm. Thatis, the longitudinal length of tension-distributing element 1160 is atleast 15% of longitudinal length L5 of stent 1500.

A first portion of band 1140 is coupled to distal tension-distributingelement 1163 is configured to be threaded through eyelet 1170 of element1163.

It is to be noted that tension-distributing element 1163 and mechanicalstructural elements 1651 may be fabricated from a single piece oftubular alloy, typically superelastic, e.g., nitinol. For someapplications tension-distributing element 1163 and mechanical structuralelements 1651 are modularly assembled.

Stent 1500 defines second tissue-engaging element 60 b.

The structural configuration of stent 1500 provided by mechanicalstructural elements 1651 may be formed by expanding a laser-slottedmetallic tube, or may be chemically etched from a flat sheet and weldedto a tube, or may be formed from a single wire, or may be formed byassembling individual wire elements, or by any other method ofconstruction known to those skilled in the art. The design of stent 1500can be laser cut from a small diameter tube, expanded to the finaldiameter, or may be cut from a large diameter tube, which is equal tothe final diameter of a fully expanded stent or which may be furtherexpanded to an even larger diameter.

Reference is now made to FIGS. 16A-B, which are schematic illustrationsof a stent system 1600 comprising a first stent 50 a and a second stent50 b shaped so as to be concentrically disposed within a lumen of stent50 a and facilitate anchoring of stent 50 a in the blood vessel, inaccordance with some applications of the present invention. Stent 50 a,as shown in FIGS. 16A-B comprises stent 1400 as described hereinabovewith reference to FIGS. 14A-C. It is to be noted, however, that stent 50a may comprise any one of the stents shown in FIGS. 1D, 13A-C, 14A-C,and 15A-B. It is to be noted that stents 50 a and 50 b define respectiveradially-expandable percutaneous, e.g., endoluminal, implants.

Stent 50 a comprises a plurality of mechanical structural elements 1651that are arranged so as to form a first tubular structure having a lumen1652 in a radially-expanded state of stent 50 a that has an innerdiameter D5 of between 18 and 45 mm, e.g., 24 mm, 28 mm, or 32 mm.

Stent 50 b comprises a radially-expandable implant 1610 that comprises aplurality of mechanical structural elements 1651 that are arranged so asto form a second tubular structure. Implant 1610 is shaped so as toprovide a plurality of tissue-engaging structures 1612 which protrudefrom the generally-tubular structure of implant 1610. For example,structures 1612 comprise barbs. Implant 1610 has an outer diameter D4 ina radially-expanded state of implant 1610, excluding tissue-engagingstructures 1612, of between 18 and 45 mm, e.g., 24 mm, 28 mm, or 32 mm.Diameter D4 enables implant 1610 to expand at least as large as theinner diameter D5 of lumen 1652 of stent 50 b. When implant 1610 expandsto assume its expanded state within lumen 1652, as shown in FIG. 16B,tissue-engaging structures 1612 extend between mechanical structuralelements 1651 of stent 50 a in order to engage and be anchored to tissueof the blood vessel. Since structures 1612 extend between mechanicalstructural elements 1651 of stent 50 a, stent 50 b of implant 1610facilitates anchoring of stent 50 a in the blood vessel.

Tissue anchor 40 defines first tissue-engaging element 60 a, stent 50 adefines second tissue-engaging element 60 b, and stent 50 b definesthird tissue-engaging element 60 c.

As described hereinabove, tissue anchor 40 is implanted in firstimplantation site 30, and then stent 50 b is deployed in the bloodvessel. Following the deploying of stent 50 b in the blood vessel,implant 1610 is position and deployed within lumen 1652 of stent 50 a.

As described hereinabove, following implantation of stent 50 a in theblood vessel, tension is applied to stent 50 a by flexible member 42(e.g., band 1140), which may cause migration of stent 50 a within theblood vessel. By deploying stent 50 b within lumen 1652 of stent 50 a,tissue-engaging structures 1612 expand between mechanical structuralelements 1651 of stent 50 a in order to engage tissue of the bloodvessel and anchor stent 50 a to the blood vessel. Additionally, theexpanding of stent 50 b within lumen 1652 of stent 50 a providesadditional radial force of stent 50 b in its expanded state againststent 50 b, in order to apply additional radial force of stent 50 aagainst the blood vessel.

The structural configuration of implant 1610 provided by mechanicalstructural elements 1651 may be formed by expanding a laser-slottedmetallic tube, or may be chemically etched from a flat sheet and weldedto a tube, or may be formed from a single wire, or may be formed byassembling individual wire elements, or by any other method ofconstruction known to those skilled in the art. The design of implant1610 can be laser cut from a small diameter tube, expanded to the finaldiameter, or may be cut from a large diameter tube, which is equal tothe final diameter of a fully expanded stent or which may be furtherexpanded to an even larger diameter. It is to be noted that mechanicalstructural elements 1651 may be arranged in a relative spatialorientation that is different from the orientation shown in FIG. 16A.

FIG. 17 shows a system 1700 for implanting second tissue-engagingelement 60 b in a blood vessel other than inferior vena cava 8 andsuperior vena cava 10, e.g., left hepatic vein 11, as shown, inaccordance with some applications of the present invention. It is to benoted that second tissue-engaging element 60 b comprises stent 1400 asdescribed hereinabove with reference to FIGS. 14A-C, by way ofillustration and not limitation. It is to be noted that secondtissue-engaging element 60 b may comprise any one of the stents orendoluminal implants shown in FIGS. 1D, 13A-C, 14A-C, 15A-B, and 16A-B.First and second tissue-engaging elements 60 a and 60 b are implanted atfirst and second implantation sites 30 and 52, in a manner as describedhereinabove with reference to FIGS. 1A-D, 7A-D, 11A-C, and 12A-C. It isto be noted that for applications in which second tissue-engagingelement 60 b is implanted in the hepatic vein, element 60 b in anexpanded state thereof has an outer diameter of between 8.5 and 12 mm,and has a length of between 17 and 36 mm.

For some applications, flexible member 42 comprises band 1140, asdescribed hereinabove.

For applications in which second implantation site 52 includes lefthepatic vein 11, flexible member 42 has a length of between 150 and 300mm, e.g., 200 mm.

It is to be noted that although implantation site 52 includes a portionof left hepatic vein 11, implantation site 52 may be a portion of aright hepatic vein or a middle hepatic vein.

Reference is made to FIGS. 1A-D. For applications in which secondimplantation site 52 includes inferior vena cava 8 or superior vena cava10, flexible member 42 has a length of between 20 and 80 mm, e.g.,between 40 and 60 mm.

It is to be noted that the scope of the present invention includesimplanting second tissue-engaging element 60 b in a coronary sinus ofthe patient. For such an application, flexible member has a length ofbetween 10 and 40 mm, e.g., 20 mm.

Reference is now made to FIGS. 13A-C, 14A-C, 15A-B, and 16A-B. It is tobe noted that any suitable configuration of tension-distributing element1160 shown in any of FIGS. 13A-C, 14A-C, 15A-B, and 16A-B may be part ofany of stents 1150, 1400, or 1500 shown in FIGS. 13A-C, 14A-C, 15A-B,and 16A-B.

FIG. 19 shows a system 2500 comprising an endoluminal percutaneousimplant 2504 comprising two or more radially-expandable rings 2502 a and2502 b which define second tissue-engaging element 60 b, in accordancewith some applications of the present invention. Rings 2502 a and 2502 bare shown as being elliptical by way of illustration and not limitation,and that rings 2502 a and 2502 b may be circular. Implant 2504 iscoupled to a portion of longitudinal member 42 at a junction betweenrings 2502 a and 2502 b, by way of illustration and not limitation.

First and second elements 60 a and 60 b are implanted in manner asdescribed hereinabove with reference to FIGS. 1A-D, 7A-D, 11A-C, and12A-C. During the advancement of implant 2504, implant 2504 is crimpedand radially-compressed within a sheath. For example, implant 2504 maybe advanced within sheath 1190, as described hereinabove with referenceto FIGS. 11A-C and 12A-C.

Implant 2504 exerts a strong radial force on tissue of the blood vesselwhile defining a low profile volume of mechanical structural elements.

It is to be noted that although second implantation site 52 includes aportion of inferior vena cava 8, second implantation site may include aportion of superior vena cava 10, hepatic vein 11, or any other suitableblood vessel.

Reference is now made to FIGS. 20-26, which are schematic illustrationsof a system 2600 comprising a first tissue-engaging element 60 a coupledto a first flexible longitudinal member 2612 at a distal first endportion 2613 of first flexible longitudinal member 2612, and a secondtissue-engaging element 60 b coupled to a second flexible longitudinalmember 2660 at a proximal first end portion 2609 of second flexiblelongitudinal member 2660, for repairing tricuspid valve 4 of heart 2 ofa patient, in accordance with some applications of the presentinvention. Second flexible longitudinal member 2660 is coupled at adistal second end portion 2662 thereof to a proximal portion of a secondflexible-longitudinal-member-coupling element 2650, e.g., by beinglooped around a portion of second flexible-longitudinal-member-couplingelement 2650, as shown. Typically, as shown in FIGS. 25 and 26, secondflexible-longitudinal-member-coupling element 2650 is shaped so as todefine a coupling interface that is not coaxial with the secondflexible-longitudinal-member-coupling element, and second flexiblelongitudinal member 2660 is fixed to the coupling interface. First andsecond end portions 2609 and 2662 of second flexible longitudinal member2660 are disposed at opposite longitudinal ends of the second flexiblelongitudinal member.

System 2600 further comprises a first delivery tool 2602 and a seconddelivery tool 2666, as described hereinbelow.

First tissue-engaging element 60 a comprises a tissue anchor 40 which isdesignated for implantation at least in part in cardiac tissue at afirst implantation site 30, such as tissue of an annulus of anatrioventricular valve, or tissue of a wall of the atrium adjacent theatrioventricular valve, as mentioned above. It is to be noted thattissue anchor 40 comprises a helical tissue anchor by way ofillustration and not limitation and that tissue anchor 40 may compriseany tissue anchor for puncturing or clamping cardiac tissue, including,but not limited to, the tissue anchors described hereinabove withreference to FIGS. 7A-D, 10A-D 11A-C, 12A-C, 13A-C, and 14A-C. Secondtissue-engaging element 60 b comprises a percutaneous implant, forexample, an endoluminal implant, e.g., stent 50, which is designated forimplantation in a portion of a blood vessel, e.g., inferior vena cava 8(such as shown in FIG. 26) or superior vena cava 10 (not shown), atsecond implantation site 52. Except as described hereinbelow, system2600 is similar to system 20 described hereinabove with reference toFIGS. 1A-D. System 2600 comprises one or more longitudinal members 42,which couple together first and second tissue-engaging elements 60 a and60 b, as described hereinabove. For such applications, system 2600comprises (1) first flexible longitudinal member 2612 (which defines afirst of the one or more longitudinal members 42) coupled at a firstportion thereof to first tissue-engaging element 60 a, and (2) secondflexible longitudinal member 2660 (which defines a second of the one ormore longitudinal members 42) coupled at a first portion thereof tosecond tissue-engaging element 60 b.

Typically, first and second flexible longitudinal members 2612 and 2660comprise a flexible biocompatible textile e.g. polyester, nylon, PTFE,ePTFE, PEEK, PEBAX™, and/or superelastic material, e.g., nitinol.Typically, first and second flexible longitudinal members 2612 and 2660comprise a plurality of fibers which are aligned, e.g., woven orintertwined, to form a fabric band, as is described hereinabove withreference to FIGS. 11A-C, 13C, and 14C. In some applications of thepresent invention, first and second flexible longitudinal members 2612and 2660 each comprise a braided polyester suture (e.g., DACRON™). Inother applications of the present invention, first and second flexiblelongitudinal members 2612 and 1660 are coated withpolytetrafluoroethylene (PTFE). In some applications of the presentinvention, first and second flexible longitudinal members 2612 and 2660each comprise a plurality of wires that are intertwined to form a ropestructure. For some applications, at least a part of each of first andsecond flexible longitudinal members 2612 and 2660 comprises a tensionspring and/or a plurality of coils.

FIG. 20 shows first delivery tool 2602 being advanced toward firstimplantation site 30 at tricuspid valve 4 through superior vena cava 10from a suitable point of entry, in a direction from B to A. As can beseen in FIG. 20, first delivery tool 2602 comprises a catheter tube2603, which is sized and configured to be introduced percutaneously.Additionally, a snare 2606 shaped to define a loop 2608 is advanced by asnare delivery tool 2604 toward first implantation site 30 at tricuspidvalve 4 through inferior vena cava 8 from a suitable point of entry, ina direction from A to B. It is to be noted that system 2600 can beadvanced in opposite direction to the one as shown in FIGS. 20-26. Thatis, first-tissue-engaging-element tool 2602 may be advanced throughinferior vena cava 8 in the direction from A to B, while snare deliverytool 2604 may be advanced through superior vena cava 10 in the directionfrom B to A.

FIGS. 21 and 22A-D show a delivery system to implant firsttissue-engaging element 60 a in tissue of the annulus of tricuspid valve4 or of the wall of atrium above the annulus. Tissue anchor 60 a isdescribed hereinabove with reference to FIGS. 1A-D and 11A-C. Distalfirst end portion 2613 of first flexible longitudinal member 2612 islooped around flexible-longitudinal-member-coupler 1242, and within aportion of opening 1244 of connecting element 1240. As describedhereinabove with reference to FIG. 11A, adapter head 1230 is coupled toa proximal portion of anchor 40 via annular loop 1246. As anchor 40 isrotated, the proximal-most coil of anchor 40 rotates freely withinannular loop 1246, and anchor 40 rotates with respect to annular loop1246.

Anchor 40 is rotated by the torque-delivering tool comprisingtorque-delivering cable 1204. As described hereinabove,torque-delivering cable 1204 is welded at a distal end thereof to firstcoupling 1220, which defines a first coupling element. As shown in FIG.22D, the first coupling element has a first-coupling-elementlongitudinal axis along an axis 2611. First coupling 1220 is shaped soas to define a first-coupling-element main body portion 2620 shaped soas to define a first-coupling-element-main-body passage 2621. Firstcoupling 1220 is shaped so as to define a first-coupling-elementsecondary body portion 2622 coaxial with main body portion 2620.First-coupling element secondary body portion 2622 is shaped so as todefine a first-coupling-element-secondary-body-portion passage 2623 thatis coaxial with first-coupling-element-main-body passage 2621. Firstcoupling 1220 is shaped so as to define a connecting element 2624 thatconnects first-coupling-element secondary body portion 2622 tofirst-coupling-element main body portion 2620. First coupling 1220 isshaped so as to define a first-coupling-element space 2625 between mainbody portion 2620 and secondary body portion 2622.

As shown in FIG. 22D, adapter head 1230 defines a second couplingelement having a longitudinal axis along axis 2611 (FIGS. 22C-D). Head1230 is shaped so as to define a second-coupling-element main bodyportion 2630 shaped so as to define a second-coupling-element-main-bodypassage 2631. Head 1230 is shaped so as to define asecond-coupling-element secondary body portion 2632 coaxial with mainbody portion 2630. The second-coupling element secondary body portion2632 is shaped so as to define asecond-coupling-element-secondary-body-portion passage 2633 that iscoaxial with second-coupling-element-main-body passage 2631. Head 1230is shaped so as to define a connecting element 2634 that connectssecond-coupling-element secondary body portion 2632 tosecond-coupling-element main body portion 2630. Head 1230 is shaped soas to define a second-coupling-element space 2635 between main bodyportion 2630 and secondary body portion 2632.

As shown in FIG. 21 (section A-A, closed position) and in FIGS. 22A-B,first coupling 1220 and head 1230 are coupled together in order toreversibly couple torque-delivering cable 1204 to anchor 40. In such aclosed position, (1) first-coupling-element secondary body portion 2622fits within second-coupling-element space 2635 of head 1230, and (2)second-coupling-element secondary body portion 2632 fits withinfirst-coupling-element space 2625 of first coupling 1220. In such amanner of these fittings, first-coupling-element-main-body passage 2621,first-coupling-element-secondary-body-portion passage 2623,second-coupling-element-main-body passage 2631, andsecond-coupling-element-secondary-body-portion passage 2633 are alignedalong axis 2611.

In order to maintain such coupling of first coupling 1220 and head 1320,an elongate longitudinal element 2610 (e.g., a rod) is reversiblydisposed within first-coupling-element-main-body passage 2621,first-coupling-element-secondary-body-portion passage 2623,second-coupling-element-main-body passage 2631, andsecond-coupling-element-secondary-body-portion passage 2633.

As shown in FIG. 22C, elongate longitudinal element 2610 is removed fromwithin the passages of coupling 1220 and of head 1230 in order tofacilitate decoupling of coupling 1220 from head 1230.

FIG. 21 (section A-A, open position) and FIGS. 22C-D show coupling 1220and head 1230 decoupled from each other. This is accomplished when (1)first-coupling-element secondary body portion 2622 is removed fromsecond-coupling-element space 2635 of head 1230, and (2)second-coupling-element secondary body portion 2632 is removed fromfirst-coupling-element space 2625 of coupling 1220. This decoupling maybe accomplished by tilting cable 1204 away from axis 2611.

Reference is again made to FIG. 21. A proximal second end portion 2615of first flexible longitudinal member 2612 is coupled to (e.g., by beinglooped around) a portion of a firstflexible-longitudinal-member-coupling element 2614. A proximal end offirst flexible-longitudinal-member-coupling element 2614 is reversiblycoupled to a distal end of a flexible longitudinal guide member 2616.For some applications, in order to enable such coupling, the proximalend of first flexible-longitudinal-member-coupling element 2614 isshaped so as to define a threaded coupling 2644 for receiving a screw2618 that is coupled to the distal end of flexible longitudinal guidemember 2616, as shown. For other applications, the proximal end of firstflexible-longitudinal-member-coupling element 2614 is reversibly coupledto the distal end of flexible longitudinal guide member 2616 using thetechniques described hereinabove with reference to FIGS. 21 and 22A-Dfor reversibly coupling torque-delivering cable 1204 to distaltissue-anchor coupling element 1233 of anchor 40, mulatis mutandis.First and second end portions 2613 and 2615 of first flexiblelongitudinal member 2612 are disposed at opposite longitudinal ends ofthe first flexible longitudinal member.

When in the closed position (shown in FIG. 21, Section A-A), cable 1204is coupled to anchor 40 and facilitates advancement of anchor 40 towardfirst implantation site 30. As the physician advances tool 2602, thephysician also advances snare 2606. Under imaging guidance,torque-delivering cable 1204 and anchor 40 are advanced through loop2608 of snare 2606, in order to create a coupling between snare 2606 andguide member 2616.

As shown in FIG. 21, torque-delivering cable 1204 is advanced within alumen of tool 2602 alongside first flexible longitudinal member 2612 andguide member 2616. Torque-delivering cable 1204 is then rotated in orderto implant anchor 40 in cardiac tissue at implantation site 30. Asdescribed hereinabove annular loop 1246 (shown in section A-A)facilitates rotation of anchor 40 with respect to (and not facilitatingrotation of) connecting element 1240, first flexible longitudinal member2612, first flexible-longitudinal-member-coupling element 2614, andguide member 2616.

Following implantation of anchor 40 at site 30, cable 1204 is decoupledfrom anchor 40, as described hereinabove, such that the open position isassumed (section A-A, FIG. 21). Torque-delivering cable 1204 is thenretracted through delivery tool 2602. Alternatively, cable 1204 isretracted at a later stage together with delivery tool 2602.

FIG. 23 shows snare 2606, via loop 2608, pulling guide member 2616 indirection A toward inferior vena cava 8. As guide member 2616 is pulled,the proximal portion of guide member 2616 slides in direction A out ofdelivery tool 2602.

As shown in the enlarged image of FIG. 23, firstflexible-longitudinal-member-coupling element 2614 is shaped so as todefine a loop 2646 through which proximal second end portion 2615 offirst flexible longitudinal member 2612 is looped, thereby firstflexible longitudinal member 2612 to firstflexible-longitudinal-member-coupling element 2614. Proximal second endportion 2615 is sewn to itself to maintain the looped coupling. Asshown, first flexible-longitudinal-member-coupling element 2614 isshaped so as to define a male coupling 2617 shaped so as to provide oneor more protrusions 2640 (e.g., an annular protrusion, as shown).Protrusion 2640 is shaped so as to provide a distal shelf 2642 (e.g., anannular shelf), which is described hereinbelow.

For some applications (configuration not shown), the distal end of guidemember 2616 may be coupled to first coupling 1220 (described hereinabovewith reference to FIGS. 21 and 22A-D), and a proximal end of firstflexible-longitudinal-member-coupling element 2614 may be coupled toadapter head 1230 (described hereinabove with reference to FIGS. 21 and22A-D; configuration not shown, but shown in FIG. 28). For suchapplications, reversible coupling of guide member 2616 to firstflexible-longitudinal-member-coupling element 2614 is accomplished viacoupling of coupling 1220 to head 1230. As described hereinabove, thecoupling of coupling 1220 and head 1230 is maintained by elongatelongitudinal element 2610 (described hereinabove with reference to FIGS.21 and 22A-D).

FIG. 24 shows guide member 2616 disposed within inferior vena cava 8following the pulling of member 2616 therethrough via snare 2606.

As shown in FIG. 25, second delivery tool 2666 is then threaded over aproximal portion of guide member 2616 in order to advance secondtissue-engaging element 60 b, second flexible longitudinal member 2660,and second flexible-longitudinal-member-coupling element 2650 towardtricuspid valve 4 from direction A. Second delivery tool 2666 isadvanced through inferior vena cava 8. As shown in FIG. 25, seconddelivery tool 2666 comprises a catheter tube 2669, which is sized andconfigured to be introduced percutaneously. An advancement tube 2667 ofsecond delivery tool 2666 is advanced through a lumen of tool 2666 andis reversibly coupled at a distal end thereof to secondflexible-longitudinal-member-coupling element 2650, or is pushed againstsecond flexible-longitudinal-member-coupling element 2650 without beingcoupled thereto. Second flexible-longitudinal-member-coupling element2650 defines a female coupling that is shaped so as to define acylindrical element, in such applications, which receives male coupling2617 of first flexible-longitudinal-member-coupling element 2614. Secondflexible-longitudinal-member-coupling element 2650 and tube 2667 slidealong guide member 2616 in order to couple together secondflexible-longitudinal-member-coupling element 2650 and firstflexible-longitudinal-member-coupling element 2614. In order to allowsuch sliding, second flexible-longitudinal-member-coupling element 2650is typically shaped so as to define a lumen therethrough, through whichguide member 2616 passes. Typically, to couple together the first andthe second flexible-longitudinal-member-coupling elements, the operatorpulls guide member 2616 and/or pushes secondflexible-longitudinal-member-coupling element 2650. Guide member 2616and second delivery tool 2666 thus allow the operator to remotely andpercutaneously control the coupling and tensioning of first and secondflexible-longitudinal-member-coupling elements 2614 and 2650, includingremotely and percutaneously inserting male coupling 2617 into the femalecoupling. These techniques also allow separate delivery of thetissue-engaging elements, using two separate delivery tools 2602 and2666. Such separate delivery simplifies the procedure for the operatoras well as allowing approaches via two or more different blood vessels,such as transfemoral, transjugular, transradial, and/or or transapicalapproaches, whichever may provide simpler access to the anchoring point.

As shown in FIGS. 25 and 26, first and second flexible longitudinalmembers 2612 and 2660 are two separate flexible longitudinal members,rather than integral longitudinal portions of a single flexiblelongitudinal member. Respective second end portions 2615 and 2662 offirst and second flexible longitudinal member 2612 and 2660 are coupledtogether via first and second flexible-longitudinal-member-couplingelements 2614 and 2650. Respective first end portions 2613 and 2609 offirst and second flexible-longitudinal-member-coupling elements 2614 and2650 are not coupled together; typically, no portions of first andsecond flexible longitudinal members 2612 and 2660, other thanrespective second end portions 2615 and 2662, are coupled together.Typically, first and second flexible longitudinal members 2612 and 2660are coupled together only by first and secondflexible-longitudinal-member-coupling elements 2614 and 2650.

For some applications, as shown in FIG. 25, the female coupling ofsecond flexible-longitudinal-member-coupling element 2650 comprises ahollow cylinder configured to receive male coupling 2617. Secondflexible-longitudinal-member-coupling element 2650 is shaped so as todefine one or more tabs 2652, which may function as pawls, biased toflex toward a longitudinal axis 2656 of the cylinder of secondflexible-longitudinal-member-coupling element 2650. As secondflexible-longitudinal-member-coupling element 2650 slides over malecoupling 2617 of first flexible-longitudinal-member-coupling element2614, the protrusion 2640 of male coupling 2617 of firstflexible-longitudinal-member-coupling element 2614 is advanceable withrespect to the one or more tabs 2652 in a first direction (e.g., aproximal direction) to push tab 2652 away from longitudinal axis 2656.First flexible-longitudinal-member-coupling element 2614 is shaped so asto define a section distal to protrusion 2640 that is narrower thanprotrusion 2640. After protrusion 2640 advances beyond tab 2652, tab2652 assumes its resting position in which it flexes toward axis 2656and closes around the narrower portion distal to protrusion 2640, asshown in Section A-A. Shelf 2642 of protrusion 2640 has a dimension thatis larger than a dimension of tab 2652 in its resting state andrestricts advancement of male coupling 2617 of firstflexible-longitudinal-member-coupling element 2614 in a second direction(e.g., a distal direction). In such a manner, tabs 2652, protrusion2640, and shelf 2642 lock first flexible-longitudinal-member-couplingelement 2614 with respect to secondflexible-longitudinal-member-coupling element 2650. For someapplications, the hollow cylinder of secondflexible-longitudinal-member-coupling element 2650 is circular, asshown, while for other applications, the hollow cylinder has a differentshape.

For some applications, a greatest outer diameter of firstflexible-longitudinal-member-coupling element 2614 is at least 1 mm, nomore than 6 mm, and/or between 1 and 6 mm, inter alia in order to allowpassage of element 2614 through catheter tube 2603 of first deliverytool 2602. For some applications, a greatest outer diameter of secondflexible-longitudinal-member-coupling element 2650 is at least 1 mm, nomore than 6 mm, and/or between 1 and 6 mm, inter alia in order to allowpassage of element 2650 through catheter tube 2669 of second deliverytool 2666.

For some applications, as shown, secondflexible-longitudinal-member-coupling element 2650 is shaped so as todefine one or more slots 2657. For some applications, protrusion 2640fits within the one or more slots 2657 in order to couple togethersecond and first flexible-longitudinal-member-coupling elements 2650 and2614. As shown, distal second end portion 2662 of second flexiblelongitudinal member 2660 is looped around a looping portion 2654 ofsecond flexible-longitudinal-member-coupling element 2650. For someapplications, male coupling 2617 is shaped so as to define one or moreinternal ridges, such as described hereinbelow with reference to FIG.33A, mutatis mutandis. The internal ridges engage tabs 2652 when thetabs enter the male coupling, thereby help prevent angular rotation offirst flexible-longitudinal-member-coupling element 2614 with respect tosecond flexible-longitudinal-member-coupling element 2650 as guidemember 2616 is unscrewed from threaded coupling 2644, as describedhereinbelow.

Following the coupling of second and firstflexible-longitudinal-member-coupling elements 2650 and 2614, tube 2667is decoupled or simply proximally withdrawn from secondflexible-longitudinal-member-coupling element 2650. Additionally, guidemember 2616 is decoupled from firstflexible-longitudinal-member-coupling element 2614, such as byunscrewing screw 2618 from threaded coupling 2644 of firstflexible-longitudinal-member-coupling element 2614 (as shown by thearrow in section A-A), or, for applications in which the proximal end offirst flexible-longitudinal-member-coupling element 2614 is reversiblycoupled to the distal end of flexible longitudinal guide member 2616using the techniques described hereinabove with reference to FIGS. 21and 22A-D, using the decoupling techniques described hereinabove withreference to FIGS. 21 and 22A-D, mutatis mutandis. Thus the operatorremotely and percutaneously decouples guide member 2616 from firstflexible-longitudinal-member-coupling element 2614. These techniquesalso allow separate delivery of the tissue-engaging elements, using twoseparate delivery tools 2602 and 2666. Such separate delivery simplifiesthe procedure for the operator as well as allowing approaches via two ormore different blood vessels, such as transfemoral, transjugular,transradial, and/or or transapical approaches, whichever may providesimpler access to the anchoring point.

Following decoupling of guide member 2616, first and secondflexible-longitudinal-member-coupling elements 2614 and 2650 remaincoupled together and thereby couple together first and second flexiblelongitudinal members 2612 and 2660.

After first and second flexible-longitudinal-member-coupling elements2614 and 2650 are coupled together, tool 2666 is retracted throughinferior vena cava 8 in order apply tension to first and second flexiblelongitudinal members 2612 and 2660 and thereby to first tissue-engagingelement 60 a, as described hereinabove, in order to adjust a distancebetween the leaflets of tricuspid valve 4 to reduce and eliminateregurgitation through and thereby repair tricuspid valve 4.

In FIG. 26, second tissue-engaging element 60 b comprising stent 50 isthen deployed in inferior vena cava 8 so as to ensure that tension ismaintained at first implantation site 30 and along first and secondflexible longitudinal members 2612 and 2660 (i.e., longitudinal members42). Stent 50 is coupled to a proximal portion of second flexiblelongitudinal member 2660. The positioning of stent 50 along inferiorvena cava 8 depends on the desired degree of tension of first and secondflexible longitudinal members 2612 and 2660 and on site 30 and of thedesired degree of repair of tricuspid valve 4.

It is to be noted that any one of stents 1150, 1400, and 1500 describedhereinabove may be used in place of any one of stents 50.

Reference is now made to FIGS. 20-26. It is to be noted that thedirection of implantation of elements 60 a and 60 b may be opposite tothose as shown in FIGS. 20-26. For example, element 60 a may beimplanted in tissue of tricuspid valve 4 by being advanced throughinferior vena cava 8, and element 60 b may be implanted in superior venacava 10.

Reference is now made to FIG. 27, which is a schematic illustration of aflexible-longitudinal-member-adjustment mechanism 2670 which is coupledto flexible longitudinal member 2660 in order to adjust a length and/ordegree of tension of member 2660, in accordance with some applicationsof the present invention. For some applications, mechanism 2670comprises a spool (not shown) configured to adjust the length/tension ofmember 2660 by winding a portion of member 2660 around the spool. Forsome applications, adjustment mechanism 2670 is coupled to firstflexible longitudinal member 2612.

An adjustment-mechanism tool 2672 is reversibly coupled to mechanism2670. As shown, tool 2672 is coupled at a distal end thereof to firstcoupling 1220 (described hereinabove with reference to FIGS. 21 and22A-D), and adjustment mechanism 2670 is coupled to adapter head 1230(described hereinabove with reference to FIGS. 21 and 22A-D). For suchapplications, reversible coupling of tool 2672 to mechanism 2670 isaccomplished via coupling of coupling 1220 to head 1230. As describedhereinabove, the coupling of coupling 1220 and head 1230 is maintainedby elongate longitudinal element 2610 (described hereinabove withreference to FIGS. 21 and 22A-D).

Flexible-longitudinal-member-adjustment mechanism 2670 may be used incombination with system 2600 described herein with reference to FIGS.20-26 and 28-32. Additionally, mechanism 2670 may be used in combinationwith systems 20, 100, 110, 120, 140, 200, 700, 800, 1000, and/or 2500.

Reference is now made to FIG. 28, which is a schematic illustration of(1) first flexible-longitudinal-member-coupling element 2614 comprisingone or more (e.g., two, as shown) radially-displaceable arms 2684, and(2) second flexible-longitudinal-member-coupling secondflexible-longitudinal-member-coupling element 2650 having one or morewalls 2682 shaped so as to define an opening 2680, in accordance withsome applications of the present invention. Opening 2680 has a dimension2688.

A proximal end of first flexible-longitudinal-member-coupling element2614 is coupled to adapter head 1230 (described hereinabove withreference to FIGS. 21 and 22A-D), or alongitudinal-guide-member-coupling element. For such applications, guidemember 2616 (not shown) is coupled at a distal end thereof to firstcoupling 1220 (described hereinabove with reference to FIGS. 21 and22A-D) and is coupled to first flexible-longitudinal-member-couplingelement 2614 via couplings 1220 and head 1230. It is to be noted thatguide member 2616 may also be coupled to firstflexible-longitudinal-member-coupling element 2614 by being screwed intoa threaded coupling 2644 of first flexible-longitudinal-member-couplingelement 2614, as described hereinabove with reference to FIGS. 21, 23,and 25.

In either embodiment, second flexible-longitudinal-member-couplingelement 2650 is slid over the guide member until opening 2680 is alignedwith arms 2684 of first flexible-longitudinal-member-coupling element2614. Second flexible-longitudinal-member-coupling element 2650 isfurther slid distally along first flexible-longitudinal-member-couplingelement 2614 such that wall 2682 compresses arms 2684 through opening2680. Once second flexible-longitudinal-member-coupling element 2650 isslid further, arms 2684 are exposed from within opening 2680 and expandto a position that is above opening 2680. Arms 2684 expand to adimension 2686 that is larger than dimension 2688 of opening 2680. Arms2684 expand to a position in which at least a portion of respectiveouter surfaces 2685 of arms 2684 is beyond and above wall 2682. In sucha manner, arms 2684 lock first flexible-longitudinal-member-couplingelement 2614 to second flexible-longitudinal-member-coupling element2650, and thereby maintain coupling of first and second flexiblelongitudinal members 2612 and 2660.

Reference is now made to FIGS. 29 and 30A-D, which are schematicillustrations of (1) first flexible-longitudinal-member-coupling element2614 comprising one or more radially-displaceable legs 2694 (e.g., two,as shown), and (2) second flexible-longitudinal-member-coupling element2650 having one or more walls 2691 (FIG. 30A) shaped so as to define anopening 2693 and one or more shelves 2692 (e.g., an annular shelf), inaccordance with some applications of the present invention.

In such applications, the female coupling is coupled to first flexiblelongitudinal member 2612, and the coupling 2617 is coupled to secondflexible longitudinal member 2660.

As shown in FIGS. 30A-B, guide member 2616 is coupled at a distal endthereof to a guide-member-coupling element 2690 (e.g., a disc, asshown). At a fist stage, element 2690 is restricted from movement in aproximal direction by shelf 2692 of element 2560. In such a manner,guide member 2616 is reversibly coupled to secondflexible-longitudinal-member-coupling element 2650.

As shown in FIGS. 29 and 30A, firstflexible-longitudinal-member-coupling element 2614 is shaped so as todefine a hollow cylinder having a lumen, and is guided along guidemember 2616 toward first flexible-longitudinal-member-coupling element2614. For some applications, the hollow cylinder of firstflexible-longitudinal-member-coupling element 2614 is circular, asshown, while for other applications, the hollow cylinder has a differentshape.

In FIG. 30B a distal end of first flexible-longitudinal-member-couplingelement 2614 and legs 2694 are advanced in a first direction (e.g., adistal direction) within a lumen of secondflexible-longitudinal-member-coupling element 2650, and legs 2694approach opening 2693. As they approach opening 2693, legs 2694 arecompressed by wall 2691 and by shelf 2692. Following the advancement oflegs 2694 beyond shelf 2692 in the first advancement direction, legs2694 are expandable to lock first flexible-longitudinal-member-couplingelement 2614 to second flexible-longitudinal-member-coupling element2650. Additionally, following the expanding of legs 2694, shelf 2692restricts advancement of legs 2694 in a second advancement direction(e.g., a proximal direction) since legs 2694 expand to a dimensionlarger than a dimension of shelf 2692.

Additionally, the positioning of legs 2694 beyond shelf 2692 displacesguide-member-coupling element 2690, as shown in FIG. 30C. Thedisplacement of element 2690 shifts the relative position of element2690 with respect to shelf 2692 of secondflexible-longitudinal-member-coupling element 2650, and element 269 maybe advanced in the second direction (e.g., the proximal direction)through and beyond opening 2693.

FIG. 30D shows the decoupling of element 2690 and guide member 2616 fromsecond flexible-longitudinal-member-coupling element 2650 andsubsequently, from first flexible-longitudinal-member-coupling element2614. As shown, first and second flexible-longitudinal-member-couplingelements 2614 and 2650 are locked together by the positioning of thedistal portion of legs 2694 distally to shelf 2692.

Wall 2691 of second flexible-longitudinal-member-coupling element 2650is shaped so as to define at least one groove 2697. As shown in FIG. 29,first flexible-longitudinal-member-coupling element 2614 is shaped so asto define at least one protrusion 2698 (e.g., an annular protrusion, asshown), which is shaped so as to fit within the at least one groove2697. The positioning of protrusion 2698 within groove 2697, as shown inFIGS. 30C-D, further locks first and secondflexible-longitudinal-member-coupling elements 2614 and 2650.

Reference is now made to FIG. 31, which is a schematic illustration of(1) first flexible-longitudinal-member-coupling element 2614 comprisingone or more protrusions 2702, and (2) secondflexible-longitudinal-member-coupling element 2650 being shaped so as todefine one or curved grooves 2700, in accordance with some applicationsof the present invention. Guide member 2616 is reversibly coupled tosecond flexible-longitudinal-member-coupling element 2650 using any ofthe coupling apparatus described herein with reference to FIGS. 21,22A-C, 23, 25, 28, 29, 30A-D, and 32.

As shown in view A, first flexible-longitudinal-member-coupling element2614 is advanced along guide member 2616 toward secondflexible-longitudinal-member-coupling element 2650. In view B,protrusion 2702 of first flexible-longitudinal-member-coupling element2614 is positioned within a portion of curved groove 2700. In view C,first flexible-longitudinal-member-coupling element 2614 is rotated inorder to position and lock protrusion 2702 within groove 2700 at an endof groove 2700. In such a manner, firstflexible-longitudinal-member-coupling element 2614 is locked to secondflexible-longitudinal-member-coupling element 2650. Following thelocking of first and second flexible-longitudinal-member-couplingelements 2614 and 2650, guide member 2616 is decoupled from secondflexible-longitudinal-member-coupling element 2650.

FIG. 32 shows guide member 2616 being coupled to firstflexible-longitudinal-member-coupling element 2614 by bring loopedaround a bar 2720 coupled to first flexible-longitudinal-member-couplingelement 2614, in accordance with some applications of the presentinvention. In such an application, secondflexible-longitudinal-member-coupling element 2650 defines the femalecoupling which is advanced along guide member 2616 toward firstflexible-longitudinal-member-coupling element 2614, which defines malecoupling 2617. Once second flexible-longitudinal-member-coupling element2650 is coupled to first flexible-longitudinal-member-coupling element2614, a first end of looped guide member 2616 is released, and thesecond end of guide member 2616 is pulled in order to unloop guidemember 2616 from around bar 2720, and thereby to decouple guide member2616 from first flexible-longitudinal-member-coupling element 2614.

Reference is now made to FIGS. 28, 29, 31, and 32. It is to be notedthat although stent 50 is shown as comprising stent 1400, any one ofstents 1150 and 1500 may be used in place of any one of stents 1400.

Reference is now made to FIGS. 20-32. The scope of the present inventionincludes coupling of first flexible-longitudinal-member-coupling element2614 to either of first and second longitudinal members 2612 and 2660and coupling of second flexible-longitudinal-member-coupling element2650 to either of longitudinal members 2612 and 2660.

Reference is now made to FIGS. 33A-B, which are schematic illustrationsof a first flexible-longitudinal-member-coupling element 3614 coupled tosecond flexible-longitudinal-member-coupling element 2650, in accordancewith an application of the present invention. Firstflexible-longitudinal-member-coupling element 3614 is an alternativeconfiguration of first flexible-longitudinal-member-coupling element2614, described hereinabove with reference to FIGS. 25-26, and may beimplemented in combination with techniques described hereinabove withreference to FIGS. 20-26, mutatis mutandis.

First flexible-longitudinal-member-coupling element 3614 comprises aplurality of male couplings 3617, disposed along the firstflexible-longitudinal-member-coupling element at respective, differentlongitudinal sites. For some applications, firstflexible-longitudinal-member-coupling element 3614 further comprises aflexible cable 3619, to which the male couplings 3617 are fixed atrespective, different longitudinal sites. The male couplings typicallysurround an entire circumference of the cable. The female coupling ofsecond flexible-longitudinal-member-coupling element 2650 is configuredto receive male couplings 3617, allow advancement of male couplings 3617through the female coupling in a first direction, and restrict (e.g.,prevent) advancement of male couplings 3617 through the female couplingin a second direction opposite the first direction. The first directionis proximal (i.e., to the left in FIGS. 33A-B), and the second directionis distal (i.e., to the right in FIGS. 33A-B). Because of thisunidirectional advancement, the coupling between first and secondflexible-longitudinal-member-couplings element 3614 and 2650 functionsas a ratchet mechanism. Typically, flexible cable 3619 is free to bend.For some applications, flexible cable 3619 is substantially nottwistable. In other words, torque applied to any longitudinal site ofthe flexible cable causes rotation of the entire flexible cable, ratherthan twisting of the cable to absorb the torque. For example, flexiblecable 3619 may comprise metal, polymer, or textile fibers.

For some applications, male couplings 3617 have respective conicalfeatures 3618. Typically, the plurality of male couplings 3617 comprisesno more than 20 male couplings. Typically, the male couplings aredisposed along first flexible-longitudinal-member-coupling element 3614at an average pitch P of at least 1 mm, no more than 12 mm, and/orbetween 1 and 12 mm. Typically, each of male couplings 3617 has a lengthof at least 4 mm, no more than 10 mm, and/or between 4 and 10 mm.

As mentioned above with reference to FIG. 25, for some applications thefemale coupling of second flexible-longitudinal-member-coupling element2650 comprises a hollow cylinder. The hollow cylinder is configured toreceive male couplings 3617, and is shaped so as to define one or moretabs 2652, which may functions as pawls, biased to flex toward a centrallongitudinal axis of the cylinder. For these applications, malecouplings 3617 are shaped so as to define respective protrusions 3640,and the protrusions and the one or more tabs are shaped and sized (a) toallow advancement of first flexible-longitudinal-member-coupling element3614 through the hollow cylinder in a proximal direction (to the left inFIGS. 33A-B), by pushing the one or more tabs away from the longitudinalaxis, and (b) to restrict advancement of firstflexible-longitudinal-member-coupling element 3614 in a distal directionopposite the proximal direction (to the right in FIGS. 33A-B). For someapplications, protrusions 3640 are shaped so as to define respectiveedges 3642, and the one or more tabs 2652 are configured to flex towardthe longitudinal axis after the advancement of the edge of the malecouplings beyond the one or more tabs 2652, so as to restrictadvancement of the male couplings with respect to the one or more tabs2652 in the distal direction.

For some applications, each of male couplings 3617 is shaped so as todefine one or more internal ridges 3660, which help prevent angularrotation of first flexible-longitudinal-member-coupling element 3614with respect to second flexible-longitudinal-member-coupling element2650 as guide member 2616 is unscrewed from threaded coupling 3644, asdescribed hereinbelow with reference to Blow-ups C and D of FIG. 34D. Asshown in the blow-up in 33A, internal ridges 3660 engage tabs 2652 whenthe tabs enter one of the male couplings, as show in FIG. 33B.

For some applications, a greatest outer diameter of firstflexible-longitudinal-member-coupling element 3614 is at least 1 mm, nomore than 6 mm, and/or between 1 and 6 mm, inter alia in order to allowpassage of element 3614 through catheter tube 2603 of first deliverytool 2602. For some applications, a greatest outer diameter of secondflexible-longitudinal-member-coupling element 2650 is at least 1 mm, nomore than 6 mm, and/or between 1 and 6 mm, inter alia in order to allowpassage of element 2650 through catheter tube 2669 of second deliverytool 2666.

Reference is now made to FIGS. 34A-E, which are schematic illustrationsof a method for deploying a system 3600 for repairing tricuspid valve 4,in accordance with an application of the present invention. System 3600comprises (a) first tissue-engaging element 60 a coupled to distal firstend portion 2613 of first flexible longitudinal member 2612, and (b)second tissue-engaging element 60 b coupled to proximal first endportion 2609 of second flexible longitudinal member 2660. System 3600further comprises first and second delivery tools 2602 and 2666.

As shown in FIG. 34A, first delivery tool 2602 is advanced toward firstimplantation site 30 at tricuspid valve 4 through interior vena cava 8from a suitable point of entry. Alternatively, the delivery tool may beadvanced through superior vena cava 10.

As shown in FIG. 34B, first tissue-engaging element 60 a is implanted intissue of the annulus of tricuspid valve 4, as described hereinabovewith reference to FIGS. 21 and 22A-D. Alternatively, firsttissue-engaging element 60 a is implanted in tissue of a wall of theatrium above the annulus. Anchor 40 of first tissue-engaging element 60a is rotated by the torque-delivering tool comprising torque-deliveringcable 1204, as described hereinabove with reference to FIGS. 21 and22A-D. Optionally, torque-delivering cable 1204 is decoupled from firsttissue-engaging element 60 a using the techniques described hereinabovewith reference to FIGS. 22A-D.

Proximal second end portion 2615 of first longitudinal member 2612 iscoupled to (e.g., by being looped around) a portion of firstflexible-longitudinal-member-coupling element 3614. A proximal end offirst flexible-longitudinal-member-coupling element 3614 is reversiblycoupled to a distal end of flexible longitudinal guide member 2616. Forsome applications, in order to enable such coupling, the proximal end offirst flexible-longitudinal-member-coupling element 3614 is shaped so asto define threaded coupling 3644 for receiving screw 2618 that iscoupled to a distal end of flexible longitudinal guide member 2616, asshown. For other applications, the proximal end of firstflexible-longitudinal-member-coupling element 3614 is reversibly coupledto the distal end of flexible longitudinal guide member 2616 using thetechniques described hereinabove with reference to FIGS. 21 and 22A-Dfor reversibly coupling torque-delivering cable 1204 to distaltissue-anchor coupling element 1233 of anchor 40, mutatis mutandis.First and second end portions 2613 and 2615 of first flexiblelongitudinal member 2612 are disposed at opposite longitudinal ends ofthe first flexible longitudinal member.

As shown in FIG. 34C, first tissue-engaging element 60 a, first flexiblelongitudinal member 2612, first flexible-longitudinal-member-couplingelement 3614, and flexible longitudinal guide member 2616 have beendeployed in the atrium. At this stage of the deployment procedure,flexible longitudinal guide member 2616 is still removably coupled tothe proximal end of first flexible-longitudinal-member-coupling element3614.

As shown in FIG. 34D, second tissue-engaging element 60 b is deployed ininferior vena cava 8, typically using second delivery tool 2666.Alternatively, the second tissue-engaging element is deployed insuperior vena cava 10, or in a coronary sinus. For some applications,the second tissue-engaging element is deployed in the same vein throughwhich first delivery tool 2602 was advanced earlier in the procedure, asshown in FIG. 34A.

Also as shown in FIG. 34D, second delivery tool 2666, including cathetertube 2669 thereof, is threaded over a proximal portion of guide member2616 in order to advance second flexible longitudinal member 2660 and asecond flexible-longitudinal-member-coupling element 2650 towardtricuspid valve 4. In the configuration shown in FIG. 34D, seconddelivery tool 2666 is advanced through inferior vena cava 8.Alternatively, the second delivery tool is advanced through superiorvena cava 10. For some applications, second delivery tool 2666 isadvanced through the same vein through which first delivery tool 2602was advanced earlier in the procedure, as shown in FIG. 34A.Alternatively, second delivery tool 2666 is advanced through a differentvein from that through which first delivery tool 2602 was advancedearlier in the procedure, such as shown in FIG. 25, mutatis mutandis;for example, one of first and second delivery tools 2602 and 2666 may beadvanced through superior vena cava 10, and the other through inferiorvena cava 8. Thus, second delivery tool 2666 is configured to deliversecond flexible longitudinal member 2660 and secondflexible-longitudinal-member-coupling element 2650 after deployment ofsecond tissue-engaging element 60 b.

For some applications in which second tissue-engaging element 60 bcomprises radially-expandable stent 50, such as described hereinabovewith reference to FIGS. 1A-D, second delivery tool 2666 is configuredand sized to pass through stent 50 when the stent is in aradially-expanded state.

As shown in Blow-up A of FIG. 34D, advancement tube 2667 of seconddelivery tool 2666 is advanced through a lumen of catheter tube 2669 oftool 2666 and is reversibly coupled at a distal end thereof to secondflexible-longitudinal-member-coupling element 2650, or is pushed againstsecond flexible-longitudinal-member-coupling element 2650 without beingcoupled thereto. The operator slides secondflexible-longitudinal-member-coupling element 2650 and tube 2667 alongguide member 2616, in order to couple secondflexible-longitudinal-member-coupling element 2650 to firstflexible-longitudinal-member-coupling element 3614. In order to allowsuch sliding, second flexible-longitudinal-member-coupling element 2650is typically shaped so as to define a lumen therethrough, through whichguide member 2616 passes. A leading (proximal-most) one of malecouplings 3617 may help direct secondflexible-longitudinal-member-coupling element 2650 onto firstflexible-longitudinal-member-coupling element 3614. Guide member 2616and second delivery tool 2666 thus allow the operator to remotely andpercutaneously control the coupling and tensioning of first and secondflexible-longitudinal-member-coupling elements 3614 and 2650, includingremotely and percutaneously inserting the leading male coupling 3617into the female coupling. These techniques also allow separate deliveryof the tissue-engaging elements, using two separate delivery tools 2602and 2666. Such separate delivery simplifies the procedure for theoperator as well as allowing approaches via two or more different bloodvessels, such as transfemoral, transjugular, transradial, and/or ortransapical approaches, whichever may provide simpler access to theanchoring point.

As shown in Blow-up B of FIG. 34D, for some applications, the femalecoupling comprises a hollow cylinder configured to receive the malecouplings. During the coupling of first and secondflexible-longitudinal-member-coupling elements 3614 and 2650, theoperator tensions first and second flexible longitudinal members 2612and 2660 by pulling one or more of male couplings 3617 into the femalecoupling. The operator pulls the one or more male couplings into thefemale coupling by pulling flexible longitudinal guide member 2616and/or pushing second flexible-longitudinal-member-coupling element 2650with tube 2667. The tensioning of first and second flexible longitudinalmembers 2612 and 2660 applies a force to first tissue-engaging element60 a, in order to adjust a distance between the leaflets of tricuspidvalve 4 to reduce and eliminate regurgitation through and thereby repairtricuspid valve 4. Guide member 2616 and second delivery tool 2666 thusallow the operator to remotely and percutaneously control the appliedtension by remotely and percutaneously pulling one or more malecouplings 3617 through the female coupling.

This providing of an adjustable length between first and secondtissue-engaging elements 60 a and 60 b allows fine-tuning of the tensionby the operator, both during and after implantation of bothtissue-engaging elements, and even after formation of neointima on thetissue-engaging elements. These techniques also allow separate deliveryof the tissue-engaging elements, using two separate delivery tools 2602and 2666. Such separate delivery simplifies the procedure for theoperator as well as allowing approaches via two or more different bloodvessels, such as transfemoral, transjugular, transradial, and/or ortransapical approaches, which may provide simpler access to theanchoring point.

As shown in Blow-up C of FIG. 34D, a desired amount of tension isapplied to first and second flexible longitudinal members 2612 and 2660.

As shown in Blow-ups C and D of FIG. 34D, guide member 2616 is decoupledfrom first flexible-longitudinal-member-coupling element 3614. For someapplications, the decoupling comprises unscrewing screw 2618 thereoffrom threaded coupling 3644 of firstflexible-longitudinal-member-coupling element 3614 (as indicated by thearrow in Blow-up D). Typically, while unscrewing screw 2618, tube 2267is held rotationally stationary in order to hold secondflexible-longitudinal-member-coupling element 2650, and thus firstflexible-longitudinal-member-coupling element 3614, rotationallystationary. Tube 2667 is then decoupled or simply proximally withdrawnfrom second flexible-longitudinal-member-coupling element 2650.Alternatively, for applications in which the proximal end of firstflexible-longitudinal-member-coupling element 3614 is reversibly coupledto the distal end of flexible longitudinal guide member 2616 using thetechniques described hereinabove with reference to FIGS. 21 and 22A-D,guide member 2616 is decoupled from firstflexible-longitudinal-member-coupling element 3614 using the decouplingtechniques described hereinabove with reference to FIGS. 21 and 22A-D,mutatis mutandis. For these applications, tube 2667 may be decoupled orsimply proximally withdrawn from secondflexible-longitudinal-member-coupling element 2650 before or afterdecoupling guide member 2616 from firstflexible-longitudinal-member-coupling element 3614. In any case, theoperator remotely and percutaneously decouples guide member 2616 fromfirst flexible-longitudinal-member-coupling element 3614.

As shown in Blow-up D of FIG. 34D and in FIG. 34E, following decouplingof guide member 2616, first and secondflexible-longitudinal-member-coupling elements 3614 and 2650 remaincoupled together and thereby couple together first and second flexiblelongitudinal members 2612 and 2660. These techniques allow separatedelivery of the tissue-engaging elements, using two separate deliverytools 2602 and 2666. Such separate delivery simplifies the procedure forthe operator as well as allowing approaches via two or more differentblood vessels, such as transfemoral, transjugular, transradial, and/oror transapical approaches, which may provide simpler access to theanchoring point.

As shown in FIGS. 34A, 34D, and 34E, first and second flexiblelongitudinal members 2612 and 2660 are two separate flexiblelongitudinal members, rather than integral longitudinal portions of asingle flexible longitudinal member. Respective second end portions 2615and 2662 of first and second flexible longitudinal member 2612 and 2660are coupled together via first and secondflexible-longitudinal-member-coupling elements 3614 and 2650. Respectivefirst end portions 2613 and 2609 of first and secondflexible-longitudinal-member-coupling elements 3614 and 2650 are notcoupled together; typically, no portions of first and second flexiblelongitudinal members 2612 and 2660, other than respective second endportions 2615 and 2662, are coupled together.

Typically, first and second flexible longitudinal members 2612 and 2660are coupled together only by first and secondflexible-longitudinal-member-coupling elements 3614 and 2650.

Reference is now made to FIGS. 35A-C, which are schematic illustrationsof another configuration of first flexible-longitudinal-member-couplingelement 3614, coupled to second flexible-longitudinal-member-couplingelement 2650, in accordance with an application of the presentinvention. Except as described below, firstflexible-longitudinal-member-coupling element 3614 may incorporate anyof the features described hereinabove with reference to FIGS. 33A-34E,and is typically deployed using the techniques of FIGS. 34A-E, mutatismutandis.

In this configuration, first flexible-longitudinal-member-couplingelement 3614 comprises a flexible chain 3700 of interconnected links3702, which are shaped so as to define respective male couplings 3617.For some applications, male couplings 3617 have respective conicalfeatures 3618. Typically, links 3702 comprise no more than 20 links.Typically, each of links 3702 has a length of at least 4 mm, no morethan 18 mm, and/or between 4 and 18 mm.

Reference is still made to FIGS. 35A-C, as well as to FIGS. 36A-B, whichare schematic illustrations of a single one of links 3702, in accordancewith an application of the present invention. In this configuration,each of links 3702 is shaped so as to define a spherical head 3710 at aproximal end 3712 of the link (typically, proximal to male coupling3617), and a spherical receptacle 3714 at a distal end 3713 of the link3716 (typically, distal to male coupling 3617). Each of the sphericalreceptacles is shaped and sized so as to couplingly receive thespherical head of a distally-adjacent link, so that the twodistally-adjacent links can articulate with respect to each other. Tothis end, an opening 3718 through a distal end of the sphericalreceptacle is sized so as to receive the spherical head of adistally-adjacent link. The opening is large enough for passagetherethrough of a neck 3720 of the adjacent spherical head, but notlarge enough for passage of the adjacent spherical head 3710. Neck 3720is narrower than spherical head 3710. For some applications, a short rod3730 connects a housing 3732 of spherical receptacle 3714 to sphericalhead 3710 of the adjacent link 3702.

Reference is now made to FIGS. 37A-B and 38A-C, which are schematicillustrations of two respective configurations of another firstflexible-longitudinal-member-coupling element 4614, coupled to secondflexible-longitudinal-member-coupling element 2650, in accordance withrespective applications of the present invention. Except as describedbelow, first flexible-longitudinal-member-coupling element 4614 mayincorporate any of the features described hereinabove with reference toFIGS. 33A-34E, and is typically deployed using the techniques of FIGS.34A-E, mutatis mutandis.

In this configuration, first flexible-longitudinal-member-couplingelement 4614 comprises a flexible cable 4616, and secondflexible-longitudinal-member-coupling element 2650 comprises a femalecoupling. The female coupling (a) comprises a hollow cylinder configuredto receive cable 4616, and (b) is shaped so as to define one or moretabs 2652, which may function as pawls, biased to flex toward a centrallongitudinal axis of the cylinder. Cable 4616 and the one or more tabs2652 are shaped and sized to allow advancement of firstflexible-longitudinal-member-coupling element 4614 through the hollowcylinder in a proximal direction, and to restrict, by friction,advancement of first flexible-longitudinal-member-coupling element 4614in a distal (loosening) direction. The tabs apply more friction to thecable in the direction of loosening (relaxing) than in the direction oftightening (tensioning).

In order to couple together first and secondflexible-longitudinal-member-coupling elements 4614 and 2650, the firstand the second flexible longitudinal members are tensioned by pullingthe flexible longitudinal guide member, and/or pushing secondflexible-longitudinal-member-coupling element 2650, such as using tube2667. For some applications, the hollow cylinder of secondflexible-longitudinal-member-coupling element 2650 is circular, asshown, while for other applications, the hollow cylinder has a differentshape. For example, cable 4616 may comprise metal, polymer, or textilefibers.

In the configuration shown in FIGS. 37A-B, a diameter of cable 4616equals between 20% and 100% of an inner diameter of the cylinder of thefemale coupling of second flexible-longitudinal-member-coupling element2650, excluding tabs 2652. Tabs 2652 are biased to flex towardlongitudinal axis 2656 of the cylinder, thereby contacting cable 4616.

In the configuration shown in FIGS. 38A-C, a diameter of cable 4616equals between 20% and 50% of the inner diameter of the cylinder of thefemale coupling of second flexible-longitudinal-member-coupling element2650, excluding tabs 2652. Tabs 2652 are biased to flex towardlongitudinal axis 2656 of the cylinder, thereby contacting cable 4616.In the configuration shown in FIGS. 38A-C, tabs 2652 are disposed atrespective, different longitudinal sites along the cylinder, e.g.,cascading, in order to apply more friction to cable 4616 by forcing itto go through a tortuous path inside the female coupling.

For some applications, a greatest outer diameter of secondflexible-longitudinal-member-coupling element 2650 is at least 1 mm, nomore than 6 mm, and/or between 1 and 6 mm, inter alia in order to allowpassage of element 2650 through catheter tube 2669 of second deliverytool 2666.

Reference is now made to FIGS. 39A-B, which are schematic illustrationsof another first flexible-longitudinal-member-coupling element 5614 andanother second flexible-longitudinal-member-coupling element 5650coupled thereto, in accordance with an application of the presentinvention. Except as described below, firstflexible-longitudinal-member-coupling element 5614 may incorporate anyof the features of first flexible-longitudinal-member-coupling element2614, described hereinabove with reference to FIGS. 25-26, and/or offirst flexible-longitudinal-member-coupling element 3614, describedhereinabove with reference to FIGS. 33A-34E. Similarly, except asdescribed below, second flexible-longitudinal-member-coupling element5650 may incorporate any of the features of secondflexible-longitudinal-member-coupling element 2650, describedhereinabove with reference to FIGS. 25-26 and/or FIGS. 33A-34E. Otherelements of this configuration typically have the features of theseelement described hereinabove, such as with reference to FIGS. 20-26and/or 33A-34E.

In this configuration, a threaded mechanism, rather than the ratchetmechanisms described hereinabove with reference to FIGS. 33A-38C, isused to couple first and second longitudinal members 2612 and 2660. Thethreaded mechanism allows percutaneous and remote (through a catheter)insertion, coupling, and both linear tensioning and relaxing of thelongitudinal members 2612 and 2660.

First flexible-longitudinal-member-coupling element 5614 is coupled tosecond end portion 2615 of first longitudinal member 2612. Firstflexible-longitudinal-member-coupling element 5614 comprises a cable5619, which is configured to be flexible and substantially not twistable(e.g., the cable does not twist more than 90 degrees over its entirelength. First flexible-longitudinal-member-coupling element 5614 furthercomprises a wire 5620, which is helically wound around cable 5619,typically at an average pitch P equal to at least one times a diameter,no more than four times a diameter, and/or between one and four times adiameter of cable 5619. Typically, the wire is fixed to the cable,typically along the entire length of the wire; for example, the wire maybe welded to the cable, or otherwise woven, braided or glued to thecable. First flexible-longitudinal-member-coupling element 5614 is thusmale. First and second end portions 2613 and 2615 of first flexiblelongitudinal member 2612 are disposed at opposite longitudinal ends ofthe first flexible longitudinal member.

Second flexible-longitudinal-member-coupling element 5650 is coupled tosecond end portion 2662 of second flexible longitudinal member 2660.Second flexible-longitudinal-member-coupling element 5650 comprises afemale coupling, which (a) comprises a hollow cylinder 5670 configuredto receive first flexible-longitudinal-member-coupling element 5614, and(b) is shaped so as to define an internal thread 5652 shaped and sizedso as to correspond with helically-wound wire 5620, so as to coupletogether first and second flexible-longitudinal-member-coupling elements5614 and 5650. First and second end portions 2609 and 2662 of secondflexible longitudinal member 2660 are disposed at opposite longitudinalends of second flexible longitudinal member 2660. Hollow cylinder 5670is shaped so as to define a lumen therethrough, and is configured toslide along flexible longitudinal guide member 2616 when the flexiblelongitudinal guide member passes through the lumen.

A distal end of flexible longitudinal guide member 2616 is reversiblycoupled to a proximal end of first flexible-longitudinal-member-couplingelement 5614. For some applications, this reversible coupling isperformed using the techniques described hereinabove with reference toFIGS. 21 and 22A-D for reversibly coupling torque-delivering cable 1204to distal tissue-anchor coupling element 1233 of anchor 40, mutatismutandis. Among other features of these techniques, the distal end offlexible longitudinal guide member 2616 comprises a first coupling 5720,similar to first coupling 1220 of torque-delivering cable 1204, and theproximal end of first flexible-longitudinal-member-coupling element 5614comprises a distal coupling element 5733, similar to distaltissue-anchor coupling element 1233. In order to maintain the couplingof first coupling 5720 and distal coupling element 5733, an elongatelongitudinal element 5710 (e.g., a rod), similar to elongatelongitudinal element 2610, is reversibly disposed within afirst-coupling-element-body passage 5721, and asecond-coupling-element-body passage 2731. Alternatively, the reversiblecoupling is performed using other coupling techniques.

During an implantation procedure, such as described hereinbelow withreference to FIG. 40D, a rotation-stabilization tube 5667 of seconddelivery tool 2666 is advanced over flexible longitudinal guide member2616 until tube 5667 reversibly engages and rotationally locks with aproximal end of second flexible-longitudinal-member-coupling element5650. For example, tube 5667 may define one or more protrusions 5668that engage respective slots 5669 defined by the proximal end of secondflexible-longitudinal-member-coupling element 5650. While tube 5667 isheld rotationally stationary, the operator remotely (i.e., through acatheter) and percutaneously rotates flexible longitudinal guide member2616, which rotates male first flexible-longitudinal-member-couplingelement 5614 with respect to female secondflexible-longitudinal-member-coupling element 5650. For someapplications, such as described hereinabove with reference to FIGS. 7A-Dand 11A-B, tissue-engaging element 66 a is configured such that theflexible longitudinal member connected thereto can rotate with respectto helical anchor 40; such rotation prevents twisting of first flexiblelongitudinal member 2612 and second flexible longitudinal member 2660 asmale first flexible-longitudinal-member-coupling element 5614 isrotated. Rotation of flexible longitudinal guide member 2616 in a firstdirection tightens the threaded coupling between the coupling elements,thereby tensioning first and second longitudinal members 2612 and 2660.Rotation in the opposite direction loosens the coupling, therebyrelaxing the first and the second longitudinal members. These techniquesthus allow remote tightening (tensioning) and relaxing (tensionreduction) of the first and the second longitudinal members. Theoperator may monitor a parameter indicative of regurgitation of thetricuspid valve during the tightening and relaxing, in order to applythe optimal level of tension.

Alternatively, the operator remotely and percutaneously rotates tube5667 while holding rotationally stationary flexible longitudinal guidemember 2616, and thus first flexible-longitudinal-member-couplingelement 5614.

For some applications, a greatest outer diameter of firstflexible-longitudinal-member-coupling element 5614 is at least 1 mm, nomore than 6 mm, and/or between 1 and 6 mm, inter alia in order to allowpassage of element 5614 through catheter tube 2603 of first deliverytool 2602. For some applications, a length of firstflexible-longitudinal-member-coupling element 5614 is at least 5 mm, nomore than 40 mm, and/or between 5 and 40 mm. For some applications, agreatest outer diameter of second flexible-longitudinal-member-couplingelement 5650 is at least 1 mm, no more than 6 mm, and/or between 1 and 6mm, inter alia in order to allow passage of element 5650 throughcatheter tube 2669 of second delivery tool 2666.

For some applications, second flexible-longitudinal-member-couplingelement 5650 is shaped so as to define a coupling interface that is notcoaxial with second flexible-longitudinal-member-coupling element 5650,and second flexible longitudinal member 2660 is fixed to the couplinginterface.

Reference is now made to FIGS. 40A-E, which are schematic illustrationsof a method for deploying a system 5600 for repairing tricuspid valve 4,in accordance with an application of the present invention. System 5600comprises (a) first tissue-engaging element 60 a coupled to distal firstend portion 2613 of first flexible longitudinal member 2612, and (b)second tissue-engaging element 60 b coupled to proximal first endportion 2609 of second flexible longitudinal member 2660. System 3600further comprises first and second delivery tools 2602 and 2666. Theelements of system 3600 typically have the features of these elementsdescribed hereinabove, such as with reference to FIGS. 20-26 and/or33A-34E.

As shown in FIG. 40A, first delivery tool 2602 is advanced toward firstimplantation site 30 at tricuspid valve 4 through interior vena cava 8from a suitable point of entry. Alternatively, the delivery tool may beadvanced through superior vena cava 10.

As shown in FIG. 40B, first tissue-engaging element 60 a is implanted intissue of the annulus of tricuspid valve 4, as described hereinabovewith reference to FIGS. 21 and 22A-D. Alternatively, firsttissue-engaging element 60 a is implanted in tissue of a wall of theatrium above the annulus. Anchor 40 of first tissue-engaging element 60a is rotated by the torque-delivering tool comprising torque-deliveringcable 1204, as described hereinabove with reference to FIGS. 21 and22A-D. Optionally, torque-delivering cable 1204 is decoupled from firsttissue-engaging element 60 a using the techniques described hereinabovewith reference to FIGS. 22A-D.

Proximal second end portion 2615 of first longitudinal member 2612 iscoupled to (e.g., by being looped around) a portion of firstflexible-longitudinal-member-coupling element 5614. A proximal end offirst flexible-longitudinal-member-coupling element 5614 is reversiblycoupled to a distal end of a flexible longitudinal guide member 2616.For some applications, in order to enable such coupling, the proximalend of first flexible-longitudinal-member-coupling element 5614 isreversibly coupled to the distal end of flexible longitudinal guidemember 2616 using the techniques described hereinabove with reference toFIGS. 21 and 22A-D for reversibly coupling torque-delivering cable 1204to distal tissue-anchor coupling element 1233 of anchor 40, mutatismutandis. First and second end portions 2613 and 2615 of first flexiblelongitudinal member 2612 are disposed at opposite longitudinal ends ofthe first flexible longitudinal member.

As shown in FIG. 40C, first tissue-engaging element 60 a, first flexiblelongitudinal member 2612, first flexible-longitudinal-member-couplingelement 5614, and flexible longitudinal guide member 2616 have beendeployed in the atrium. At this stage of the deployment procedure,flexible longitudinal guide member 2616 is still removably coupled tothe proximal end of first flexible-longitudinal-member-coupling element5614.

As shown in FIG. 40D, second tissue-engaging element 60 b is deployed ininferior vena cava 8, typically using second delivery tool 2666.Alternatively, the second tissue-engaging element is deployed insuperior vena cava 10, or in a coronary sinus. For some applications,the second tissue-engaging element is deployed in the same vein throughwhich first delivery tool 2602 was advanced earlier in the procedure, asshown in FIG. 40A.

Also as shown in FIG. 40D, second delivery tool 2666, including cathetertube 2669 thereof, is threaded over a proximal portion of guide member2616 in order to advance second flexible longitudinal member 2660 and asecond flexible-longitudinal-member-coupling element 5650 towardtricuspid valve 4. In the configuration shown in FIG. 40D, seconddelivery tool 2666 is advanced through inferior vena cava 8.Alternatively, the second delivery tool is advanced through superiorvena cava 10. For some applications, second delivery tool 2666 isadvanced through the same vein through which first delivery tool 2602was advanced earlier in the procedure, as shown in FIG. 40A.Alternatively, second delivery tool 2666 is advanced through a differentvein from that through which first delivery tool 2602 was advancedearlier in the procedure, such as shown in FIG. 25, mutatis mutandis,for example, one of first and second delivery tools 2602 and 2666 may beadvanced through superior vena cava 10, and the other through inferiorvena cava 8. Thus, second delivery tool 2666 is configured to deliversecond flexible longitudinal member 2660 and secondflexible-longitudinal-member-coupling element 5650 after deployment ofsecond tissue-engaging element 60 b.

For some applications in which second tissue-engaging element 60 bcomprises radially-expandable stent 50, such as described hereinabovewith reference to FIGS. 1A-D, second delivery tool 2666 is configuredand sized to pass through stent 50 when the stent is in aradially-expanded state.

Second delivery tool 2666 of system 5600 typically comprisesrotation-stabilization tube 5667, rather than advancement tube 2667(described hereinabove with reference to FIG. 40D). As shown in Blow-upA of FIG. 40D, rotation-stabilization tube 5667 of second delivery tool2666 is advanced through a lumen of catheter tube 2669 of tool 2666until tube 5667 reversibly engages and rotationally locks with aproximal end of second flexible-longitudinal-member-coupling element5650. The operator slides second flexible-longitudinal-member-couplingelement 5650 and tube 5667 along guide member 2616, in order to couplesecond flexible-longitudinal-member-coupling element 5650 to firstflexible-longitudinal-member-coupling element 5614. In order to allowsuch sliding, second flexible-longitudinal-member-coupling element 5650is typically shaped so as to define a lumen therethrough, through whichguide member 2616 passes. Guide member 2616 and second delivery tool2666 thus allow the operator to remotely and percutaneously control thecoupling and tensioning of first and secondflexible-longitudinal-member-coupling elements 5614 and 5650, includingremotely and percutaneously inserting the leading (proximal) end offirst flexible-longitudinal-member-coupling elements 5614 into femalesecond flexible-longitudinal-member-coupling elements 5650.

As shown in Blow-up B of FIG. 40D, during the coupling of first andsecond flexible-longitudinal-member-coupling elements 5614 and 5650, theoperator tensions first and second flexible longitudinal members 2612and 2660 by pulling one or more of male couplings 3617 into the femalecoupling. While tube 5667 is held rotationally stationary, the operatorremotely (i.e., through catheter tube 2669) and percutaneously rotatesflexible longitudinal guide member 2616, which rotates male firstflexible-longitudinal-member-coupling element 5614 with respect tofemale second flexible-longitudinal-member-coupling element 5650.Rotation of flexible longitudinal guide member 2616 in a first directiontightens the threaded coupling between the coupling elements, therebytensioning first and second longitudinal members 2612 and 2660. Rotationin the opposite direction, which is also performed by the operatorremotely and percutaneously, loosens the coupling, thereby relaxing thefirst and the second longitudinal members.

The tensioning of first and second flexible longitudinal members 2612and 2660 applies a force to first tissue-engaging element 60 a, in orderto adjust a distance between the leaflets of tricuspid valve 4 to reduceand eliminate regurgitation through and thereby repair tricuspid valve4. Guide member 2616 and second delivery tool 2666 thus allow theoperator to remotely and percutaneously control the applied tension byremotely and percutaneously rotating first and secondflexible-longitudinal-member-coupling elements 5614 and 5650 withrespect to each other.

This providing of an adjustable length between first and secondtissue-engaging elements 60 a and 60 b allows fine-tuning of the tensionby the operator, both during and after implantation of bothtissue-engaging elements, and even after formation of neointima on thetissue-engaging elements. These techniques also allow separate deliveryof the tissue-engaging elements, using two separate delivery tools 2602and 2666. Such separate delivery simplifies the procedure for theoperator as well as allowing approaches via two or more different bloodvessels, such as transfemoral, transjugular, transradial, and/or ortransapical approaches, which may provide simpler access to theanchoring point.

As shown in Blow-up C of FIG. 40D, once a desired amount of tension hasbeen applied to first and second flexible longitudinal members 2612 and2660, tube 5667 is decoupled and proximally withdrawn from secondflexible-longitudinal-member-coupling element 5650.

As shown in Blow-ups C and D of FIG. 40D, guide member 2616 is remotelyand percutaneously decoupled from firstflexible-longitudinal-member-coupling element 5614, such as using thedecoupling techniques described hereinabove with reference to FIGS. 21and 22A-D, mutatis mutandis.

As shown in Blow-up D of FIG. 40D and in FIG. 40E, following decouplingof guide member 2616, first and secondflexible-longitudinal-member-coupling elements 5614 and 5650 remaincoupled together and thereby couple together first and second flexiblelongitudinal members 2612 and 2660.

As shown in FIGS. 40A, 40D, and 40E, first and second flexiblelongitudinal members 2612 and 2660 are two separate flexiblelongitudinal members, rather than integral longitudinal portions of asingle flexible longitudinal member. Respective second end portions 2615and 2662 of first and second flexible longitudinal member 2612 and 2660are coupled together via first and secondflexible-longitudinal-member-coupling elements 5614 and 5650. Respectivefirst end portions 2613 and 2609 of first and secondflexible-longitudinal-member-coupling elements 5614 and 5650 are notcoupled together; typically, no portions of first and second flexiblelongitudinal members 2612 and 2660, other than respective second endportions 2615 and 2662, are coupled together. Typically, first andsecond flexible longitudinal members 2612 and 2660 are coupled togetheronly by first and second flexible-longitudinal-member-coupling elements5614 and 5650.

Reference is now made to FIGS. 1A-D, 2A-B, 3A-C, 4A-C, 5A-B, 6, 7A-D, 8,9, 10A-D, 11A-C, 12A-C, 13A-C, 14A-C, 15A-B, 16A-B, 17, 18A-B, 19-32,33A-34E, 35A-36B, 37A-38C, 39A-B, and 40A-E. It is to be noted thatapparatus and methods described herein for repairing tricuspid valve 4may also be applied to repair any other heart valve of the patient,e.g., a mitral valve, a pulmonary valve, or an aortic valve. For suchapplications, second implantation site 52 may include a portion of ablood vessel that is in contact with the left atrium of the patient,e.g., a pulmonary vein, a portion of the wall of the left atrium, aportion of the annulus of the mitral valve, or a portion of the leftventricle of the heart of the patient, and first implantation site 30may include a portion of the wall of the left atrium, a portion of theannulus of the mitral valve, or a portion of the left ventricle of theheart of the patient.

Reference is again made to FIGS. 1A-D, 2A-B, 3A-C, 4A-C, 5A-B, 6, 7A-D,8, 9, 10A-D, 11A-C, 12A-C, 13A-C, 14A-C, 15A-B, 16A-B, 17, 18A-B, 19-32,33A-34E, 35A-36B, 37A-38C, 39A-B, and 40A-E. It is to be noted that anyone of stents 1150, 1400, and 1500 may be used in place of any one ofstents 50 shown in FIGS. 1D, 2A-B, 3A-C, 4B-C, 6, 7A-D, 8, 9, 16A-B, 17,34D-E, and 40D-E. It is to be further noted that system 1000 shown inFIGS. 11A-C and 12A-C may be used to implant any tissue anchor 40described herein and stent 50 described herein. Specifically, system1000 shown in FIGS. 11A-C and 12A-C may be used in place of system 200,as described hereinabove with reference to FIGS. 7A-D.

Reference is yet again made to FIGS. 1A-D, 2A-B, 3A-C, 4A-C, 5A-B, 6,7A-D, 8, 9, 10A-D, 11A-C, 12A-C, 13A-C, 14A-C, 15A-B, 16A-B, 17, 18A-B,19-32, 33A-34E, 35A-36B, 37A-38C, 39A-B, and 40A-E. It is to be notedthat any suitable number of tissue-engaging elements 60 may be implantedin and/or grasp cardiac tissue, depending on the needs of a givenpatient. Typically, one or more tissue-engaging elements 60 is/areimplanted in cardiac tissue (e.g., tissue of the annulus, tissue of thewall of the atrium adjacent the valve, or tissue of the wall of theventricle adjacent the valve) in a vicinity of the valve that is betweenthe middle of the anterior leaflet and the middle of the posteriorleaflet, e.g., at the commissure between the middle of the anteriorleaflet and the middle of the posterior leaflet. For such anapplication, pulling together implantation sites 30 and 52 pullsanterior leaflet 14 toward septal leaflet 12 and thereby achievesbicuspidization of tricuspid valve 4. It is to be noted, however, thattissue-engaging elements 60 may be implanted in portions of tissue inthe vicinity of any portion of the annulus of valve 4.

Reference is still yet again made to FIGS. 1A-D, 2A-B, 3A-C, 4A-C, and5A-B, 6, 7A-D, 8, 9, 10A-D, 11A-C, 12A-C, 13A-C, 14A-C, 15A-B, 16A-B,17, 18A-B, 19-32, 33A-34E, 35A-36B, 37A-38C, 39A-B, and 40A-E. It is tobe noted that the adjustment of the distance between the respectiveimplantation sites of the tissue-engaging elements 60 is facilitated byadjusting mechanism 150 following initial implantation of thetissue-engaging elements 60 and the repair of the valve and/or theadjustment of the heart wall geometry.

The scope of the present invention includes embodiments described in thefollowing applications, which are assigned to the assignee of thepresent application and are incorporated herein by reference. In anembodiment, techniques and apparatus described in one or more of thefollowing patent applications are combined with techniques and apparatusdescribed herein:

-   -   U.S. Pat. No. 8,475,525 to Maisano et al.    -   US Patent Application Publication 2012/0035712    -   US Patent Application Publication 2013/0325115    -   US Patent Application Publication 2013/0046380    -   PCT Publication WO 2013/179295

It will be appreciated by persons skilled in the art that the presentinvention is not limited to what has been particularly shown anddescribed hereinabove. Rather, the scope of the present inventionincludes both combinations and subcombinations of the various featuresdescribed hereinabove, as well as variations and modifications thereofthat are not in the prior art, which would occur to persons skilled inthe art upon reading the foregoing description.

The invention claimed is:
 1. A system for repairing an atrioventricularvalve of a patient, the system comprising: first and secondtissue-engaging elements, configured for implantation at first andsecond implantation sites of the patient, respectively; a first flexiblelongitudinal member, which is coupled at a first distal end portionthereof to the first tissue-engaging element, and which comprises anelement selected from the group consisting of: a braided polyestersuture and a plurality of wires that are intertwined to form a ropestructure; a second flexible longitudinal member, which is coupled at afirst proximal end portion thereof to the second tissue-engagingelement, and which comprises an element selected from the groupconsisting of: a braided polyester suture and a plurality of wires thatare intertwined to form a rope structure; a firstflexible-longitudinal-member-coupling element coupled to a secondproximal end portion of the first flexible longitudinal member, whereinthe first distal and the second proximal end portions of the firstflexible longitudinal member are disposed at opposite longitudinal endsof the first flexible longitudinal member; and a secondflexible-longitudinal-member-coupling element coupled to a second distalend portion of the second flexible longitudinal member, wherein thefirst proximal and the second distal end portions of the second flexiblelongitudinal member are disposed at opposite longitudinal ends of thesecond flexible longitudinal member, wherein the first and the secondflexible-longitudinal-member-coupling elements are configured to becouplable together during an implantation procedure to couple togetherthe first and the second flexible longitudinal elements, wherein thefirst flexible-longitudinal-member-coupling element comprises one ormore male couplings, which are shaped so as to define one or morerespective protrusions that protrude radially outward such that thefirst flexible-longitudinal-member-coupling element defines one or morerespective sections distal to the respective protrusions that arenarrower than the respective protrusions, wherein the secondflexible-longitudinal-member-coupling element is shaped so as to definea hollow cylinder that is shaped to receive the one or more malecouplings of the first flexible-longitudinal-member-coupling element,and wherein the hollow cylinder is shaped so as to define one or moretabs biased to flex toward a central longitudinal axis of the hollowcylinder so as to: allow proximal movement of the one or moreprotrusions of the first flexible-longitudinal-member-coupling elementwith respect to the one or more tabs in a proximal direction to push theone or more tabs away from the longitudinal axis, and thereafter closearound one of the one or more narrower sections of the firstflexible-longitudinal-member-coupling element, thereby restrictingdistal movement of the first flexible-longitudinal-member-couplingelement with respect to the second flexible-longitudinal-member-couplingelement.
 2. The system according to claim 1, wherein the firstflexible-longitudinal-member-coupling element comprises a plurality ofmale couplings, disposed along the firstflexible-longitudinal-member-coupling element at respective, differentlongitudinal sites, and wherein the hollow cylinder of the secondflexible-longitudinal-member-coupling element shaped to receive the malecouplings, allow advancement of the male couplings through the hollowcylinder in the proximal direction, and restrict advancement of the malecouplings through the hollow cylinder in a distal direction opposite theproximal direction.
 3. The system according to claim 2, wherein thefirst flexible-longitudinal-member-coupling element comprises a flexiblechain of interconnected links, which are shaped so as to define the malecouplings, respectively.
 4. The system according to claim 2, wherein thefirst flexible-longitudinal-member-coupling element comprises a flexiblecable to which the male couplings are fixed at the respective, differentlongitudinal sites.
 5. The system according to claim 1, wherein the oneor more male couplings have respective conical features.
 6. The systemaccording to claim 1, wherein one of the first and the secondtissue-engaging elements comprises a helical tissue anchor.
 7. Thesystem according to claim 1, wherein one of the first and the secondtissue-engaging elements comprises a radially-expandable stentconfigured to be implanted in a portion of a blood vessel.
 8. The systemaccording to claim 1, wherein the one or more protrusions are shaped soas to provide one or more respective distal shelfs, which have adimension that is larger than a dimension of the one or more tabs intheir resting state and restricts advancement of the one or more malecouplings of the first flexible-longitudinal-member-coupling element ina distal direction, such that the one or more tabs, the one or moreprotrusions, and the one or more shelfs lock the firstflexible-longitudinal-member-coupling element with respect to the secondflexible-longitudinal-member-coupling element.
 9. A method for repairingan atrioventricular valve of a patient, the method comprising:implanting, at a first implantation site of the patient, a firsttissue-engaging element, to which a first distal end portion of a firstflexible longitudinal member is coupled, wherein a firstflexible-longitudinal-member-coupling element is coupled to a secondproximal end portion of the first flexible longitudinal element, whereinthe first distal and the second proximal end portions of the firstflexible longitudinal member are disposed at opposite longitudinal endsof the first flexible longitudinal member, wherein the first flexiblelongitudinal element comprises an element selected from the groupconsisting of: a braided polyester suture and a plurality of wires thatare intertwined to form a rope structure, and wherein the firstflexible-longitudinal-member-coupling element comprises one or more malecouplings, which are shaped so as to define one or more respectiveprotrusions that protrude radially outward such that the firstflexible-longitudinal-member-coupling element defines one or morerespective sections distal to the respective protrusions that arenarrower than the respective protrusions; implanting, at a secondimplantation site of the patient, a second tissue-engaging element, towhich a first proximal end portion of a second flexible longitudinalmember is coupled, wherein a second tissue-engaging element is coupledto a second distal end portion of the second flexible longitudinalmember, wherein the first proximal and the second distal end portions ofthe second flexible longitudinal member are disposed at oppositelongitudinal ends of the second flexible longitudinal member, whereinthe second flexible longitudinal element comprises an element selectedfrom the group consisting of: a braided polyester suture and a pluralityof wires that are intertwined to form a rope structure, and wherein thesecond flexible-longitudinal-member-coupling element is shaped so as todefine a hollow cylinder that is shaped to receive the one or more malecouplings of the first flexible-longitudinal-member-coupling element;and coupling together the first and the secondflexible-longitudinal-member-coupling elements in situ by inserting theone or more male couplings of the firstflexible-longitudinal-member-coupling element into the hollow cylinder,thereby coupling together the first and the second flexible longitudinalmembers, wherein the hollow cylinder is shaped so as to define one ormore tabs biased to flex toward a central longitudinal axis of thehollow cylinder so as to: allow proximal movement of the one or moreprotrusions of the first flexible-longitudinal-member-coupling elementwith respect to the one or more tabs in a proximal direction to push theone or more tabs away from the longitudinal axis, and thereafter closearound one of the one or more narrower sections of the firstflexible-longitudinal-member-coupling element, thereby restrictingdistal movement of the first flexible-longitudinal-member-couplingelement with respect to the second flexible-longitudinal-member-couplingelement.
 10. The method according to claim 9, wherein coupling togetherthe first and the second flexible-longitudinal-member-coupling elementscomprises tensioning the first and the second flexible longitudinalmembers by pulling one or more of the one or more male couplings throughthe hollow cylinder.
 11. The method according to claim 9, wherein thefirst flexible-longitudinal-member-coupling element comprises aplurality of male couplings, disposed along the firstflexible-longitudinal-member-coupling element at respective, differentlongitudinal sites, wherein hollow cylinder of the secondflexible-longitudinal-member-coupling element shaped to receive the malecouplings, allow advancement of the male couplings through the hollowcylinder in the proximal direction, and restrict advancement of the malecouplings through the hollow cylinder in a distal direction opposite theproximal direction, and wherein coupling together the first and thesecond flexible-longitudinal-member-coupling elements comprisestensioning the first and the second flexible longitudinal members bypulling one or more of the one or more male couplings into the hollowcylinder.
 12. The method according to claim 11, wherein the malecouplings have respective conical features.
 13. The method according toclaim 11, wherein the first flexible-longitudinal-member-couplingelement comprises a flexible chain of interconnected links, which areshaped so as to define the male couplings, respectively.
 14. The methodaccording to claim 11, wherein the firstflexible-longitudinal-member-coupling element comprises a flexible cableto which the male couplings are fixed at the respective, differentlongitudinal sites.
 15. The method according to claim 9, comprisingrepairing the atrioventricular valve by applying tension between thefirst and the second implantation sites using the first and the secondflexible longitudinal members.
 16. The method according to claim 15,further comprising adjusting a distance between the first and the secondimplantation sites after repairing the atrioventricular valve.
 17. Themethod according to claim 15, wherein repairing the atrioventricularvalve comprises remodeling the atrioventricular valve by drawingtogether leaflets of the atrioventricular valve by applying tension tothe second flexible longitudinal member.
 18. The method according toclaim 9, wherein implanting the first and the second tissue-engagingelements comprises implanting the first and the second tissue-engagingelements on opposite sides of the atrioventricular valve.
 19. The methodaccording to claim 9, wherein one of the first and the secondtissue-engaging elements comprises a helical tissue anchor.
 20. Themethod according to claim 9, wherein one of the first and the secondtissue-engaging elements comprises a radially-expandable stent, andwherein implanting the one of the first and the second tissue-engagingelements comprises expanding the radially-expandable stent in a portionof a blood vessel.
 21. The method according to claim 9, wherein the oneor more protrusions are shaped so as to provide one or more respectivedistal shelfs, which have a dimension that is larger than a dimension ofthe one or more tabs in their resting state and restricts advancement ofthe one or more male couplings of the firstflexible-longitudinal-member-coupling element in a distal direction,such that the one or more tabs, the one or more protrusions, and the oneor more shelfs lock the first flexible-longitudinal-member-couplingelement with respect to the second flexible-longitudinal-member-couplingelement.